37 files changed, 249 insertions, 1799 deletions
diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
deleted file mode 100644
index ab0456b..0000000
--- a/.github/CONTRIBUTING.md
+++ /dev/null
@@ -1,3 +0,0 @@
-Please do not send/request features related to image manipulation. i3lock’s
-support for background images is intentionally kept minimal, you should do all
-pre-processing in external tools.
diff --git a/.github/ISSUE_TEMPLATE.md b/.github/ISSUE_TEMPLATE.md
deleted file mode 100644
index 591fdfe..0000000
--- a/.github/ISSUE_TEMPLATE.md
+++ /dev/null
@@ -1,29 +0,0 @@
-<!--
-PLEASE HELP US PROCESS GITHUB ISSUES FASTER BY PROVIDING THE FOLLOWING INFORMATION.
-->
-## I'm submitting a…
-<!-- Please check one of the following options with "x" -->
-<pre>
-[ ] Bug
-[ ] Feature Request
-[ ] Other (Please describe in detail)
-</pre>
-## Current Behavior
-<!-- Describe the current behavior -->
-## Expected Behavior
-<!-- Describe the desired behavior you expect after mitigation of the issue -->
-## Reproduction Instructions
-<!--
-For bug reports, please provide detailed instructions on how the bug can be reproduced.
-For feature requests, you can remove this section.
-->
-## Environment
-Output of `i3lock --version`:
-<pre>
-i3lock version: 
-</pre>
diff --git a/.gitignore b/.gitignore
index eb37b56..bc9fbfb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,31 +1,10 @@
-/i3lock
+/i3lock-extended
 *.o
 tags
 *.swp
-################################################################################
+# We recommend building in a subdirectory called build.
-# https://raw.githubusercontent.com/github/gitignore/master/Autotools.gitignore
+# If you chose a different directory name,
-################################################################################
+# it is up to you to arrange for it to be ignored by git,
+# e.g. by listing your directory in .git/info/exclude.
-# http://www.gnu.org/software/automake
+/build
-Makefile.in
-/ar-lib
-/test-driver
-# http://www.gnu.org/software/autoconf
-/autom4te.cache
-/autoscan.log
-/autoscan-*.log
-/aclocal.m4
-/compile
-/config.h.in
-/config.guess
-/config.sub
-/configure
-/configure.scan
-/depcomp
-/install-sh
-/missing
-/stamp-h1
diff --git a/CHANGELOG b/CHANGELOG
index b9bd8ad..126cf58 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,9 @@
+2023-03-18 i3lock-extended 2.2.14
+ • Fetch and sync with i3lock 2.14.1
+ • Update README.md
 2020-12-29 i3lock-extended 2.2.13a
 • Fix and sort the help (-h) string
diff --git a/I3LOCK_VERSION b/I3LOCK_VERSION
deleted file mode 100644
index 7ea8f83..0000000
--- a/I3LOCK_VERSION
+++ /dev/null
@@ -1 +0,0 @@
-2.2.13a
diff --git a/INSTALL.md b/INSTALL.md
index cb2cde9..1c726b5 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -1,6 +1,6 @@
 i3lock - improved screen locker
 ===============================
-[i3lock](https://i3wm.org/i3lock/)> is a simple screen locker like slock.
+[i3lock](https://i3wm.org/i3lock/) is a simple screen locker like slock.
 After starting it, you will see a white screen (you can configure the
 color/an image). You can return to your screen by entering your password.
@@ -44,8 +44,16 @@ Requirements
 Running i3lock
 -------------
-Simply invoke the 'i3lock' command. To get out of it, enter your password and
-press enter.
+To test i3lock, you can directly run the `i3lock` command. To get out of it,
+enter your password and press enter.
+For a more permanent setup, we strongly recommend using `xss-lock` so that the
+screen is locked *before* your laptop suspends:
+```
+xss-lock --transfer-sleep-lock -- i3lock --nofork
+```
 On OpenBSD the `i3lock` binary needs to be setgid `auth` to call the
 authentication helpers, e.g. `/usr/libexec/auth/login_passwd`.
@@ -58,17 +66,11 @@ i3lock unless you have a reason to do so.
 First install the dependencies listed in requirements section, then run these
 commands (might need to be adapted to your OS):
 ```
-autoreconf --force --install
 rm -rf build/
 mkdir -p build && cd build/
-../configure \
+meson .. -Dprefix=/usr
-  --prefix=/usr \
+ninja
-  --sysconfdir=/etc \
-  --disable-sanitizers
-make
 ```
 Upstream
diff --git a/LICENSE b/LICENSE
index 756d014..8b98561 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,5 +1,5 @@
 i3lock-extended
-Copyright (C) 2020 Simeon Simeonov
+Copyright (C) 2020-2023 Simeon Simeonov
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
diff --git a/Makefile.am b/Makefile.am
deleted file mode 100644
index f9323b8..0000000
--- a/Makefile.am
+++ /dev/null
@@ -1,61 +0,0 @@
-@CODE_COVERAGE_RULES@
-echo-version:
-        @echo "@I3LOCK_VERSION@"
-bin_PROGRAMS = i3lock-extended
-dist_man1_MANS = i3lock-extended.1
-pamddir = $(sysconfdir)/pam.d
-pamd_files = pam/i3lock-extended
-pamd_DATA = $(pamd_files)
-AM_CPPFLAGS = \
-        @AX_EXTEND_SRCDIR_CPPFLAGS@
-i3lock_extended_CFLAGS = \
-        $(AM_CFLAGS) \
-        $(XCB_CFLAGS) \
-        $(XCB_IMAGE_CFLAGS) \
-        $(XCB_UTIL_CFLAGS) \
-        $(XCB_UTIL_XRM_CFLAGS) \
-        $(XKBCOMMON_CFLAGS) \
-        $(CAIRO_CFLAGS) \
-        -DEXTRAS \
-        $(CODE_COVERAGE_CFLAGS)
-i3lock_extended_CPPFLAGS = \
-        $(AM_CPPFLAGS) \
-        $(CODE_COVERAGE_CPPFLAGS)
-i3lock_extended_LDADD = \
-        $(XCB_LIBS) \
-        $(XCB_IMAGE_LIBS) \
-        $(XCB_UTIL_LIBS) \
-        $(XCB_UTIL_XRM_LIBS) \
-        $(XKBCOMMON_LIBS) \
-        $(CAIRO_LIBS) \
-        $(CODE_COVERAGE_LDFLAGS)
-i3lock_extended_SOURCES = \
-        cursors.h \
-        dpi.c \
-        dpi.h \
-        extras.c \
-        extras.h \
-        i3lock.c \
-        i3lock.h \
-        randr.c \
-        randr.h \
-        unlock_indicator.c \
-        unlock_indicator.h \
-        xcb.c \
-        xcb.h
-EXTRA_DIST = \
-        $(pamd_files) \
-        CHANGELOG \
-        LICENSE \
-        README.md \
-        I3LOCK_VERSION
diff --git a/README.md b/README.md
index 80b6ac1..9ea58fe 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 # i3lock-extended
 i3lock-extended is a fork of i3lock (https://github.com/i3/i3lock).
-It was started by Simeon Simeonov (sgs @ Freenode) as a small hack, 
+It was started by Simeon Simeonov (sgs @ LiberaChat) as a small hack, 
 implementing a LED-clock on top of an existing and robust screensaver.
 i3lock-extended adds some additional functionality and is a free-software
@@ -40,7 +40,9 @@ extended revision if used].
 ### Gentoo
   ```bash
-   layman -a sgs
+   # add sgs' custom repository using app-eselect/eselect-repository
+   eselect repository add sgs
   emerge x11-misc/i3lock-extended
   ```
@@ -58,25 +60,26 @@ Install the package:
   ```
-### From source
+### From source (meson > 0.55.0)
   ```bash
-   wget https://simeon.simeonov.no/programs/i3lock_extended/downloads/i3lock-extended-<version>.tar.xz
+   wget https://github.com/blackm0re/i3lock_extended/releases/download/<version>/i3lock-extended-<version>.tar.xz
-   tar Jxvf i3lock-extended-<version>.tar.xz && cd i3lock-extended-<version>
+   tar Jxvf i3lock-extended-<version>.tar.xz
-   ./configure --prefix=/usr --sysconfdir=/etc --disable-sanitizers
+   cd i3lock-extended-<version>
-   make
+   meson setup build --prefix=/usr
-   make install
+   meson compile -C build
+   sudo meson install -C build
   ```
-### From git
+### From git (meson > 0.55.0)
   ```bash
-   git clone https://github.com/blackm0re/i3lock-extended.git && cd i3lock-extended
+   git clone https://github.com/blackm0re/i3lock-extended.git
-   autoreconf --force --install
+   cd i3lock-extended
-   ./configure --prefix=/usr --sysconfdir=/etc --disable-sanitizers
+   meson setup build --prefix=/usr
-   make
+   meson compile -C build
-   make install
+   sudo meson install -C build
   ```
@@ -112,12 +115,12 @@ i3lock-extended is hosted on GitHub: https://github.com/blackm0re/i3lock-extende
 ## Author
-Simeon Simeonov - sgs @ Freenode
+Simeon Simeonov - sgs @ LiberaChat
 ## [License](https://github.com/blackm0re/i3lock-extended/blob/master/LICENSE)
-Copyright 2020 Simeon Simeonov
+Copyright 2020-2023 Simeon Simeonov
 Licensed under the GPLv3: http://www.gnu.org/licenses/gpl-3.0.html
diff --git a/configure.ac b/configure.ac
deleted file mode 100644
index d7c4f04..0000000
--- a/configure.ac
+++ /dev/null
@@ -1,155 +0,0 @@
-#                                               -*- Autoconf -*-
-# Run autoreconf -fi to generate a configure script from this file.
-AC_PREREQ([2.69])
-AC_INIT([i3lock-extended], [2.2.13a], [https://simeon.simeonov.no])
-# For AX_EXTEND_SRCDIR
-AX_ENABLE_BUILDDIR
-AM_INIT_AUTOMAKE([foreign subdir-objects -Wall no-dist-gzip dist-bzip2])
-# Default to silent rules, use V=1 to get verbose compilation output.
-AM_SILENT_RULES([yes])
-# Make it possible to disable maintainer mode to disable re-generation of build
-# system files.
-AM_MAINTAINER_MODE([enable])
-AC_CONFIG_SRCDIR([i3lock.c])
-AC_CONFIG_HEADERS([config.h])
-AC_CONFIG_MACRO_DIR([m4])
-dnl Verify macros defined in m4/ such as AX_SANITIZERS are not present in the
-dnl output, i.e. are replaced as expected. This line results in a better error
-dnl message when using aclocal < 1.13 (which does not understand
-dnl AC_CONFIG_MACRO_DIR) without passing the -I m4 parameter.
-m4_pattern_forbid([AX_SANITIZERS])
-# Verify we are using GNU make because we use '%'-style pattern rules in
-# Makefile.am, which are a GNU make extension. Pull requests to replace
-# '%'-style pattern rules with a more portable alternative are welcome.
-AX_CHECK_GNU_MAKE
-AS_VAR_IF([_cv_gnu_make_command], [""], [AC_MSG_ERROR([the i3lock Makefile.am requires GNU make])])
-AX_EXTEND_SRCDIR
-AS_IF([test -d ${srcdir}/.git],
-      [
-        VERSION="$(git -C ${srcdir} describe --tags --abbrev=0)"
-        I3LOCK_VERSION="$(git -C ${srcdir} describe --tags --always) ($(git -C ${srcdir} log --pretty=format:%cd --date=short -n1), branch \\\"$(git -C ${srcdir} describe --tags --always --all | sed s:heads/::)\\\")"
-        # Mirrors what libi3/is_debug_build.c does:
-        is_release=$(test $(echo "${I3LOCK_VERSION}" | cut -d '(' -f 1 | wc -m) -lt 10 && echo yes || echo no)
-      ],
-      [
-        VERSION="$(cut -d '-' -f 1 ${srcdir}/I3LOCK_VERSION | cut -d ' ' -f 1)"
-        I3LOCK_VERSION="$(sed -e 's/@<:@\"?\\@:>@/\\&/g' ${srcdir}/I3LOCK_VERSION)"
-        is_release="$(grep -q non-git ${srcdir}/I3LOCK_VERSION && echo no || echo yes)"
-      ])
-AC_SUBST([I3LOCK_VERSION], [$I3LOCK_VERSION])
-AC_DEFINE_UNQUOTED([I3LOCK_VERSION], ["${I3LOCK_VERSION}"], [i3lock version])
-AX_CODE_COVERAGE
-dnl is_release must be lowercase because AX_CHECK_ENABLE_DEBUG calls m4_tolower
-dnl on its fourth argument.
-AX_CHECK_ENABLE_DEBUG([yes], , [UNUSED_NDEBUG], [$is_release])
-AC_PROG_CC_C99
-# For strnlen() and vasprintf().
-AC_USE_SYSTEM_EXTENSIONS
-# Checks for typedefs, structures, and compiler characteristics.
-AC_CHECK_HEADER_STDBOOL
-dnl The error message should include the specific type which could not be
-dnl found, but I do not see a way to achieve that.
-AC_CHECK_TYPES([mode_t, off_t, pid_t, size_t, ssize_t], , [AC_MSG_FAILURE([cannot find required type])])
-# Checks for library functions.
-AC_FUNC_FORK
-AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK
-AC_FUNC_STRNLEN
-AC_CHECK_FUNCS([atexit dup2 ftruncate getcwd gettimeofday localtime_r memchr memset mkdir rmdir setlocale socket strcasecmp strchr strdup strerror strncasecmp strndup strrchr strspn strstr strtol strtoul], , [AC_MSG_FAILURE([cannot find the $ac_func function, which i3lock requires])])
-AC_CHECK_FUNCS([explicit_bzero])
-# Checks for libraries.
-AC_SEARCH_LIBS([floor], [m], , [AC_MSG_FAILURE([cannot find the required floor() function despite trying to link with -lm])])
-# libev does not ship with a pkg-config file :(.
-AC_SEARCH_LIBS([ev_run], [ev], , [AC_MSG_FAILURE([cannot find the required ev_run() function despite trying to link with -lev])])
-AC_SEARCH_LIBS([shm_open], [rt])
-# Only disable PAM on OpenBSD where i3lock uses BSD Auth instead
-case "$host" in
-        *-openbsd*)
-        # Nothing yet.
-        ;;
-        *)
-        AC_SEARCH_LIBS([pam_authenticate], [pam])
-        ;;
-esac
-AC_SEARCH_LIBS([iconv_open], [iconv], , [AC_MSG_FAILURE([cannot find the required iconv_open() function despite trying to link with -liconv])])
-dnl Each prefix corresponds to a source tarball which users might have
-dnl downloaded in a newer version and would like to overwrite.
-PKG_CHECK_MODULES([XCB], [xcb xcb-xkb xcb-xinerama xcb-randr])
-PKG_CHECK_MODULES([XCB_IMAGE], [xcb-image])
-PKG_CHECK_MODULES([XCB_UTIL], [xcb-event xcb-util xcb-atom])
-PKG_CHECK_MODULES([XCB_UTIL_XRM], [xcb-xrm])
-PKG_CHECK_MODULES([XKBCOMMON], [xkbcommon xkbcommon-x11])
-PKG_CHECK_MODULES([CAIRO], [cairo])
-# Checks for programs.
-AC_PROG_AWK
-AC_PROG_CPP
-AC_PROG_INSTALL
-AC_PROG_MAKE_SET
-AC_PROG_RANLIB
-AC_PROG_LN_S
-AM_PROG_AR
-AX_FLAGS_WARN_ALL
-AX_CHECK_COMPILE_FLAG([-Wunused-value], [AX_APPEND_FLAG([-Wunused-value], [AM_CFLAGS])])
-AC_SUBST(AM_CFLAGS)
-# Checks for header files.
-AC_CHECK_HEADERS([fcntl.h float.h inttypes.h limits.h locale.h netinet/in.h paths.h stddef.h stdint.h stdlib.h string.h sys/param.h sys/socket.h sys/time.h unistd.h], , [AC_MSG_FAILURE([cannot find the $ac_header header, which i3lock requires])])
-AC_CONFIG_FILES([Makefile])
-# Enable address sanitizer for non-release builds. The performance hit is a
-# 50% increase of wallclock time for the testsuite on my machine.
-if test x$is_release = xyes; then
-        default_sanitizers=
-else
-        default_sanitizers=address
-fi
-AX_SANITIZERS(, [$default_sanitizers], [AC_DEFINE([I3LOCK_ASAN_ENABLED], [], [Enable ASAN])])
-AC_OUTPUT
-in_git_worktree=`git rev-parse --is-inside-work-tree 2>/dev/null`
-if [[ "$in_git_worktree" = "true" ]]; then
-        git_dir=`git rev-parse --git-dir 2>/dev/null`
-        srcdir=`dirname "$git_dir"`
-        exclude_dir=`pwd | sed "s,^$srcdir,,g"`
-        if ! grep -q "^$exclude_dir" "$git_dir/info/exclude"; then
-                echo "$exclude_dir" >> "$git_dir/info/exclude"
-        fi
-fi
-echo \
-"--------------------------------------------------------------------------------
-build configured:
-AS_HELP_STRING([i3lock-extended version:], [`echo ${I3LOCK_VERSION} | sed 's,\\\\,,g'`])
-AS_HELP_STRING([is release version:], [${is_release}])
-AS_HELP_STRING([enable debug flags:], [${ax_enable_debug}])
-AS_HELP_STRING([code coverage:], [${CODE_COVERAGE_ENABLED}])
-AS_HELP_STRING([enabled sanitizers:], [${ax_enabled_sanitizers}])
-To compile, run:
-  cd `pwd` && make -j8
--------------------------------------------------------------------------------"
diff --git a/extras.c b/extras.c
index fa78c86..4e321ff 100644
--- a/extras.c
+++ b/extras.c
@@ -1,6 +1,6 @@
 /*
 * This file is part of i3lock-extended
- * Copyright (C) 2020 Simeon Simeonov
+ * Copyright (C) 2020-2023 Simeon Simeonov
 * i3lock-extended is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
diff --git a/i3lock-extended.1 b/i3lock-extended.1
index ee97c45..dbac52a 100644
--- a/i3lock-extended.1
+++ b/i3lock-extended.1
@@ -8,7 +8,7 @@
 .fi
 ..
-.TH i3lock\-extended 1 "DECEMBER 2020" Linux "User Manuals"
+.TH i3lock\-extended 1 "MARCH 2023" Linux "User Manuals"
 .SH NAME
 i3lock\-extended \- improved screen locker
diff --git a/i3lock.c b/i3lock.c
index 48edddb..aee9b2a 100644
--- a/i3lock.c
+++ b/i3lock.c
@@ -1,6 +1,6 @@
 /*
 * This file is part of i3lock-extended
- * Copyright (C) 2020 Simeon Simeonov
+ * Copyright (C) 2020-2023 Simeon Simeonov
 * i3lock-extended is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
@@ -106,7 +106,7 @@ i3lock_led_clock_t i3lock_led_clock = {"ffff00",
 char *display_text = NULL;
 #endif
-char color[7] = "ffffff";
+char color[7] = "a3a3a3";
 uint32_t last_resolution[2];
 xcb_window_t win;
 static xcb_cursor_t cursor;
@@ -132,9 +132,9 @@ int failed_attempts = 0;
 bool show_failed_attempts = false;
 bool retry_verification = false;
-static struct xkb_state *xkb_state;
+struct xkb_state *xkb_state;
 static struct xkb_context *xkb_context;
-static struct xkb_keymap *xkb_keymap;
+struct xkb_keymap *xkb_keymap;
 static struct xkb_compose_table *xkb_compose_table;
 static struct xkb_compose_state *xkb_compose_state;
 static uint8_t xkb_base_event;
@@ -360,41 +360,6 @@ static void input_done(void) {
    if (debug_mode)
        fprintf(stderr, "Authentication failure\n");
-    /* Get state of Caps and Num lock modifiers, to be displayed in
-     * STATE_AUTH_WRONG state */
-    xkb_mod_index_t idx, num_mods;
-    const char *mod_name;
-    num_mods = xkb_keymap_num_mods(xkb_keymap);
-    for (idx = 0; idx < num_mods; idx++) {
-        if (!xkb_state_mod_index_is_active(xkb_state, idx, XKB_STATE_MODS_EFFECTIVE))
-            continue;
-        mod_name = xkb_keymap_mod_get_name(xkb_keymap, idx);
-        if (mod_name == NULL)
-            continue;
-        /* Replace certain xkb names with nicer, human-readable ones. */
-        if (strcmp(mod_name, XKB_MOD_NAME_CAPS) == 0)
-            mod_name = "Caps Lock";
-        else if (strcmp(mod_name, XKB_MOD_NAME_ALT) == 0)
-            mod_name = "Alt";
-        else if (strcmp(mod_name, XKB_MOD_NAME_NUM) == 0)
-            mod_name = "Num Lock";
-        else if (strcmp(mod_name, XKB_MOD_NAME_LOGO) == 0)
-            mod_name = "Super";
-        char *tmp;
-        if (modifier_string == NULL) {
-            if (asprintf(&tmp, "%s", mod_name) != -1)
-                modifier_string = tmp;
-        } else if (asprintf(&tmp, "%s, %s", modifier_string, mod_name) != -1) {
-            free(modifier_string);
-            modifier_string = tmp;
-        }
-    }
    auth_state = STATE_AUTH_WRONG;
    failed_attempts += 1;
    clear_input();
@@ -459,7 +424,7 @@ static void handle_key_press(xcb_key_press_event_t *event) {
                return;
            case XKB_COMPOSE_COMPOSED:
                /* xkb_compose_state_get_utf8 doesn't include the terminating byte in the return value
-             * as xkb_keysym_to_utf8 does. Adding one makes the variable n consistent. */
+                 * as xkb_keysym_to_utf8 does. Adding one makes the variable n consistent. */
                n = xkb_compose_state_get_utf8(xkb_compose_state, buffer, sizeof(buffer)) + 1;
                ksym = xkb_compose_state_get_one_sym(xkb_compose_state);
                composed = true;
@@ -1131,7 +1096,7 @@ int main(int argc, char *argv[]) {
    while ((o = getopt_long(argc, argv, optstring, longopts, &longoptind)) != -1) {
        switch (o) {
            case 'v':
-                errx(EXIT_SUCCESS, "version " I3LOCK_VERSION " © 2010 Michael Stapelberg, 2017-2020 Simeon Simeonov");
+                errx(EXIT_SUCCESS, "version " I3LOCK_VERSION " © 2010 Michael Stapelberg, 2020-2023 Simeon Simeonov");
            case 'n':
                dont_fork = true;
                break;
diff --git a/cursors.h b/include/cursors.h
index bfce895..bfce895 100644
--- a/cursors.h
+++ b/include/cursors.h
diff --git a/dpi.h b/include/dpi.h
index 35840d2..35840d2 100644
--- a/dpi.h
+++ b/include/dpi.h
diff --git a/extras.h b/include/extras.h
index c78ffff..4f791d8 100644
--- a/extras.h
+++ b/include/extras.h
@@ -1,6 +1,6 @@
 /*
 * This file is part of i3lock-extended
- * Copyright (C) 2020 Simeon Simeonov
+ * Copyright (C) 2020-2023 Simeon Simeonov
 * i3lock-extended is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
diff --git a/i3lock.h b/include/i3lock.h
index 6cf7694..6cf7694 100644
--- a/i3lock.h
+++ b/include/i3lock.h
diff --git a/randr.h b/include/randr.h
index 510a7cb..510a7cb 100644
--- a/randr.h
+++ b/include/randr.h
diff --git a/unlock_indicator.h b/include/unlock_indicator.h
index 581d028..581d028 100644
--- a/unlock_indicator.h
+++ b/include/unlock_indicator.h
diff --git a/xcb.h b/include/xcb.h
index 3555c58..3555c58 100644
--- a/xcb.h
+++ b/include/xcb.h
diff --git a/m4/ax_append_flag.m4 b/m4/ax_append_flag.m4
deleted file mode 100644
index 08f2e07..0000000
--- a/m4/ax_append_flag.m4
+++ /dev/null
@@ -1,71 +0,0 @@
-# ===========================================================================
-#      http://www.gnu.org/software/autoconf-archive/ax_append_flag.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_APPEND_FLAG(FLAG, [FLAGS-VARIABLE])
-#
-# DESCRIPTION
-#
-#   FLAG is appended to the FLAGS-VARIABLE shell variable, with a space
-#   added in between.
-#
-#   If FLAGS-VARIABLE is not specified, the current language's flags (e.g.
-#   CFLAGS) is used.  FLAGS-VARIABLE is not changed if it already contains
-#   FLAG.  If FLAGS-VARIABLE is unset in the shell, it is set to exactly
-#   FLAG.
-#
-#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION.
-#
-# LICENSE
-#
-#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
-#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
-#
-#   This program is free software: you can redistribute it and/or modify it
-#   under the terms of the GNU General Public License as published by the
-#   Free Software Foundation, either version 3 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
-#   Public License for more details.
-#
-#   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
-#serial 6
-AC_DEFUN([AX_APPEND_FLAG],
-[dnl
-AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_SET_IF
-AS_VAR_PUSHDEF([FLAGS], [m4_default($2,_AC_LANG_PREFIX[FLAGS])])
-AS_VAR_SET_IF(FLAGS,[
-  AS_CASE([" AS_VAR_GET(FLAGS) "],
-    [*" $1 "*], [AC_RUN_LOG([: FLAGS already contains $1])],
-    [
-     AS_VAR_APPEND(FLAGS,[" $1"])
-     AC_RUN_LOG([: FLAGS="$FLAGS"])
-    ])
-  ],
-  [
-  AS_VAR_SET(FLAGS,[$1])
-  AC_RUN_LOG([: FLAGS="$FLAGS"])
-  ])
-AS_VAR_POPDEF([FLAGS])dnl
-])dnl AX_APPEND_FLAG
diff --git a/m4/ax_cflags_warn_all.m4 b/m4/ax_cflags_warn_all.m4
deleted file mode 100644
index 1f07799..0000000
--- a/m4/ax_cflags_warn_all.m4
+++ /dev/null
@@ -1,122 +0,0 @@
-# ===========================================================================
-#    http://www.gnu.org/software/autoconf-archive/ax_cflags_warn_all.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_CFLAGS_WARN_ALL   [(shellvar [,default, [A/NA]])]
-#   AX_CXXFLAGS_WARN_ALL [(shellvar [,default, [A/NA]])]
-#   AX_FCFLAGS_WARN_ALL  [(shellvar [,default, [A/NA]])]
-#
-# DESCRIPTION
-#
-#   Try to find a compiler option that enables most reasonable warnings.
-#
-#   For the GNU compiler it will be -Wall (and -ansi -pedantic) The result
-#   is added to the shellvar being CFLAGS, CXXFLAGS, or FCFLAGS by default.
-#
-#   Currently this macro knows about the GCC, Solaris, Digital Unix, AIX,
-#   HP-UX, IRIX, NEC SX-5 (Super-UX 10), Cray J90 (Unicos 10.0.0.8), and
-#   Intel compilers.  For a given compiler, the Fortran flags are much more
-#   experimental than their C equivalents.
-#
-#    - $1 shell-variable-to-add-to : CFLAGS, CXXFLAGS, or FCFLAGS
-#    - $2 add-value-if-not-found : nothing
-#    - $3 action-if-found : add value to shellvariable
-#    - $4 action-if-not-found : nothing
-#
-#   NOTE: These macros depend on AX_APPEND_FLAG.
-#
-# LICENSE
-#
-#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
-#   Copyright (c) 2010 Rhys Ulerich <rhys.ulerich@gmail.com>
-#
-#   This program is free software; you can redistribute it and/or modify it
-#   under the terms of the GNU General Public License as published by the
-#   Free Software Foundation; either version 3 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
-#   Public License for more details.
-#
-#   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
-#serial 15
-AC_DEFUN([AX_FLAGS_WARN_ALL],[dnl
-AS_VAR_PUSHDEF([FLAGS],[_AC_LANG_PREFIX[]FLAGS])dnl
-AS_VAR_PUSHDEF([VAR],[ac_cv_[]_AC_LANG_ABBREV[]flags_warn_all])dnl
-AC_CACHE_CHECK([m4_ifval($1,$1,FLAGS) for maximum warnings],
-VAR,[VAR="no, unknown"
-ac_save_[]FLAGS="$[]FLAGS"
-for ac_arg dnl
-in "-warn all  % -warn all"   dnl Intel
-   "-pedantic  % -Wall"       dnl GCC
-   "-xstrconst % -v"          dnl Solaris C
-   "-std1      % -verbose -w0 -warnprotos" dnl Digital Unix
-   "-qlanglvl=ansi % -qsrcmsg -qinfo=all:noppt:noppc:noobs:nocnd" dnl AIX
-   "-ansi -ansiE % -fullwarn" dnl IRIX
-   "+ESlit     % +w1"         dnl HP-UX C
-   "-Xc        % -pvctl[,]fullmsg" dnl NEC SX-5 (Super-UX 10)
-   "-h conform % -h msglevel 2" dnl Cray C (Unicos)
-   #
-do FLAGS="$ac_save_[]FLAGS "`echo $ac_arg | sed -e 's,%%.*,,' -e 's,%,,'`
-   AC_COMPILE_IFELSE([AC_LANG_PROGRAM],
-                     [VAR=`echo $ac_arg | sed -e 's,.*% *,,'` ; break])
-done
-FLAGS="$ac_save_[]FLAGS"
-])
-AS_VAR_POPDEF([FLAGS])dnl
-AX_REQUIRE_DEFINED([AX_APPEND_FLAG])
-case ".$VAR" in
-     .ok|.ok,*) m4_ifvaln($3,$3) ;;
-   .|.no|.no,*) m4_default($4,[m4_ifval($2,[AX_APPEND_FLAG([$2], [$1])])]) ;;
-   *) m4_default($3,[AX_APPEND_FLAG([$VAR], [$1])]) ;;
-esac
-AS_VAR_POPDEF([VAR])dnl
-])dnl AX_FLAGS_WARN_ALL
-dnl  implementation tactics:
-dnl   the for-argument contains a list of options. The first part of
-dnl   these does only exist to detect the compiler - usually it is
-dnl   a global option to enable -ansi or -extrawarnings. All other
-dnl   compilers will fail about it. That was needed since a lot of
-dnl   compilers will give false positives for some option-syntax
-dnl   like -Woption or -Xoption as they think of it is a pass-through
-dnl   to later compile stages or something. The "%" is used as a
-dnl   delimiter. A non-option comment can be given after "%%" marks
-dnl   which will be shown but not added to the respective C/CXXFLAGS.
-AC_DEFUN([AX_CFLAGS_WARN_ALL],[dnl
-AC_LANG_PUSH([C])
-AX_FLAGS_WARN_ALL([$1], [$2], [$3], [$4])
-AC_LANG_POP([C])
-])
-AC_DEFUN([AX_CXXFLAGS_WARN_ALL],[dnl
-AC_LANG_PUSH([C++])
-AX_FLAGS_WARN_ALL([$1], [$2], [$3], [$4])
-AC_LANG_POP([C++])
-])
-AC_DEFUN([AX_FCFLAGS_WARN_ALL],[dnl
-AC_LANG_PUSH([Fortran])
-AX_FLAGS_WARN_ALL([$1], [$2], [$3], [$4])
-AC_LANG_POP([Fortran])
-])
diff --git a/m4/ax_check_compile_flag.m4 b/m4/ax_check_compile_flag.m4
deleted file mode 100644
index ca36397..0000000
--- a/m4/ax_check_compile_flag.m4
+++ /dev/null
@@ -1,74 +0,0 @@
-# ===========================================================================
-#   http://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
-#
-# DESCRIPTION
-#
-#   Check whether the given FLAG works with the current language's compiler
-#   or gives an error.  (Warnings, however, are ignored)
-#
-#   ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
-#   success/failure.
-#
-#   If EXTRA-FLAGS is defined, it is added to the current language's default
-#   flags (e.g. CFLAGS) when the check is done.  The check is thus made with
-#   the flags: "CFLAGS EXTRA-FLAGS FLAG".  This can for example be used to
-#   force the compiler to issue an error when a bad flag is given.
-#
-#   INPUT gives an alternative input source to AC_COMPILE_IFELSE.
-#
-#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
-#   macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG.
-#
-# LICENSE
-#
-#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
-#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
-#
-#   This program is free software: you can redistribute it and/or modify it
-#   under the terms of the GNU General Public License as published by the
-#   Free Software Foundation, either version 3 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
-#   Public License for more details.
-#
-#   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
-#serial 4
-AC_DEFUN([AX_CHECK_COMPILE_FLAG],
-[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
-AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl
-AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [
-  ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS
-  _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1"
-  AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
-    [AS_VAR_SET(CACHEVAR,[yes])],
-    [AS_VAR_SET(CACHEVAR,[no])])
-  _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags])
-AS_VAR_IF(CACHEVAR,yes,
-  [m4_default([$2], :)],
-  [m4_default([$3], :)])
-AS_VAR_POPDEF([CACHEVAR])dnl
-])dnl AX_CHECK_COMPILE_FLAGS
diff --git a/m4/ax_check_enable_debug.m4 b/m4/ax_check_enable_debug.m4
deleted file mode 100644
index f99d75f..0000000
--- a/m4/ax_check_enable_debug.m4
+++ /dev/null
@@ -1,124 +0,0 @@
-# ===========================================================================
-#   http://www.gnu.org/software/autoconf-archive/ax_check_enable_debug.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_CHECK_ENABLE_DEBUG([enable by default=yes/info/profile/no], [ENABLE DEBUG VARIABLES ...], [DISABLE DEBUG VARIABLES NDEBUG ...], [IS-RELEASE])
-#
-# DESCRIPTION
-#
-#   Check for the presence of an --enable-debug option to configure, with
-#   the specified default value used when the option is not present.  Return
-#   the value in the variable $ax_enable_debug.
-#
-#   Specifying 'yes' adds '-g -O0' to the compilation flags for all
-#   languages. Specifying 'info' adds '-g' to the compilation flags.
-#   Specifying 'profile' adds '-g -pg' to the compilation flags and '-pg' to
-#   the linking flags. Otherwise, nothing is added.
-#
-#   Define the variables listed in the second argument if debug is enabled,
-#   defaulting to no variables.  Defines the variables listed in the third
-#   argument if debug is disabled, defaulting to NDEBUG.  All lists of
-#   variables should be space-separated.
-#
-#   If debug is not enabled, ensure AC_PROG_* will not add debugging flags.
-#   Should be invoked prior to any AC_PROG_* compiler checks.
-#
-#   IS-RELEASE can be used to change the default to 'no' when making a
-#   release.  Set IS-RELEASE to 'yes' or 'no' as appropriate. By default, it
-#   uses the value of $ax_is_release, so if you are using the AX_IS_RELEASE
-#   macro, there is no need to pass this parameter.
-#
-#     AX_IS_RELEASE([git-directory])
-#     AX_CHECK_ENABLE_DEBUG()
-#
-# LICENSE
-#
-#   Copyright (c) 2011 Rhys Ulerich <rhys.ulerich@gmail.com>
-#   Copyright (c) 2014, 2015 Philip Withnall <philip@tecnocode.co.uk>
-#
-#   Copying and distribution of this file, with or without modification, are
-#   permitted in any medium without royalty provided the copyright notice
-#   and this notice are preserved.
-#serial 5
-AC_DEFUN([AX_CHECK_ENABLE_DEBUG],[
-    AC_BEFORE([$0],[AC_PROG_CC])dnl
-    AC_BEFORE([$0],[AC_PROG_CXX])dnl
-    AC_BEFORE([$0],[AC_PROG_F77])dnl
-    AC_BEFORE([$0],[AC_PROG_FC])dnl
-    AC_MSG_CHECKING(whether to enable debugging)
-    ax_enable_debug_default=m4_tolower(m4_normalize(ifelse([$1],,[no],[$1])))
-    ax_enable_debug_is_release=m4_tolower(m4_normalize(ifelse([$4],,
-                                                              [$ax_is_release],
-                                                              [$4])))
-    # If this is a release, override the default.
-    AS_IF([test "$ax_enable_debug_is_release" = "yes"],
-      [ax_enable_debug_default="no"])
-    m4_define(ax_enable_debug_vars,[m4_normalize(ifelse([$2],,,[$2]))])
-    m4_define(ax_disable_debug_vars,[m4_normalize(ifelse([$3],,[NDEBUG],[$3]))])
-    AC_ARG_ENABLE(debug,
-        [AS_HELP_STRING([--enable-debug=]@<:@yes/info/profile/no@:>@,[compile with debugging])],
-        [],enable_debug=$ax_enable_debug_default)
-    # empty mean debug yes
-    AS_IF([test "x$enable_debug" = "x"],
-      [enable_debug="yes"])
-    # case of debug
-    AS_CASE([$enable_debug],
-      [yes],[
-        AC_MSG_RESULT(yes)
-        CFLAGS="${CFLAGS} -g -O0"
-        CXXFLAGS="${CXXFLAGS} -g -O0"
-        FFLAGS="${FFLAGS} -g -O0"
-        FCFLAGS="${FCFLAGS} -g -O0"
-        OBJCFLAGS="${OBJCFLAGS} -g -O0"
-      ],
-      [info],[
-        AC_MSG_RESULT(info)
-        CFLAGS="${CFLAGS} -g"
-        CXXFLAGS="${CXXFLAGS} -g"
-        FFLAGS="${FFLAGS} -g"
-        FCFLAGS="${FCFLAGS} -g"
-        OBJCFLAGS="${OBJCFLAGS} -g"
-      ],
-      [profile],[
-        AC_MSG_RESULT(profile)
-        CFLAGS="${CFLAGS} -g -pg"
-        CXXFLAGS="${CXXFLAGS} -g -pg"
-        FFLAGS="${FFLAGS} -g -pg"
-        FCFLAGS="${FCFLAGS} -g -pg"
-        OBJCFLAGS="${OBJCFLAGS} -g -pg"
-        LDFLAGS="${LDFLAGS} -pg"
-      ],
-      [
-        AC_MSG_RESULT(no)
-        dnl Ensure AC_PROG_CC/CXX/F77/FC/OBJC will not enable debug flags
-        dnl by setting any unset environment flag variables
-        AS_IF([test "x${CFLAGS+set}" != "xset"],
-          [CFLAGS=""])
-        AS_IF([test "x${CXXFLAGS+set}" != "xset"],
-          [CXXFLAGS=""])
-        AS_IF([test "x${FFLAGS+set}" != "xset"],
-          [FFLAGS=""])
-        AS_IF([test "x${FCFLAGS+set}" != "xset"],
-          [FCFLAGS=""])
-        AS_IF([test "x${OBJCFLAGS+set}" != "xset"],
-          [OBJCFLAGS=""])
-      ])
-    dnl Define various variables if debugging is disabled.
-    dnl assert.h is a NOP if NDEBUG is defined, so define it by default.
-    AS_IF([test "x$enable_debug" = "xyes"],
-      [m4_map_args_w(ax_enable_debug_vars, [AC_DEFINE(], [,,[Define if debugging is enabled])])],
-      [m4_map_args_w(ax_disable_debug_vars, [AC_DEFINE(], [,,[Define if debugging is disabled])])])
-    ax_enable_debug=$enable_debug
-])
diff --git a/m4/ax_check_gnu_make.m4 b/m4/ax_check_gnu_make.m4
deleted file mode 100644
index 6762e9e..0000000
--- a/m4/ax_check_gnu_make.m4
+++ /dev/null
@@ -1,84 +0,0 @@
-# ===========================================================================
-#     http://www.gnu.org/software/autoconf-archive/ax_check_gnu_make.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_CHECK_GNU_MAKE()
-#
-# DESCRIPTION
-#
-#   This macro searches for a GNU version of make. If a match is found:
-#
-#     * The makefile variable `ifGNUmake' is set to the empty string, otherwise
-#       it is set to "#". This is useful for including a special features in a
-#       Makefile, which cannot be handled by other versions of make.
-#     * The variable `_cv_gnu_make_command` is set to the command to invoke
-#       GNU make if it exists, the empty string otherwise.
-#     * The variable `ax_cv_gnu_make_command` is set to the command to invoke
-#       GNU make by copying `_cv_gnu_make_command`, otherwise it is unset.
-#     * If GNU Make is found, its version is extracted from the output of
-#       `make --version` as the last field of a record of space-separated
-#       columns and saved into the variable `ax_check_gnu_make_version`.
-#
-#   Here is an example of its use:
-#
-#   Makefile.in might contain:
-#
-#     # A failsafe way of putting a dependency rule into a makefile
-#     $(DEPEND):
-#             $(CC) -MM $(srcdir)/*.c > $(DEPEND)
-#
-#     @ifGNUmake@ ifeq ($(DEPEND),$(wildcard $(DEPEND)))
-#     @ifGNUmake@ include $(DEPEND)
-#     @ifGNUmake@ endif
-#
-#   Then configure.in would normally contain:
-#
-#     AX_CHECK_GNU_MAKE()
-#     AC_OUTPUT(Makefile)
-#
-#   Then perhaps to cause gnu make to override any other make, we could do
-#   something like this (note that GNU make always looks for GNUmakefile
-#   first):
-#
-#     if  ! test x$_cv_gnu_make_command = x ; then
-#             mv Makefile GNUmakefile
-#             echo .DEFAULT: > Makefile ;
-#             echo \  $_cv_gnu_make_command \$@ >> Makefile;
-#     fi
-#
-#   Then, if any (well almost any) other make is called, and GNU make also
-#   exists, then the other make wraps the GNU make.
-#
-# LICENSE
-#
-#   Copyright (c) 2008 John Darrington <j.darrington@elvis.murdoch.edu.au>
-#   Copyright (c) 2015 Enrico M. Crisostomo <enrico.m.crisostomo@gmail.com>
-#
-#   Copying and distribution of this file, with or without modification, are
-#   permitted in any medium without royalty provided the copyright notice
-#   and this notice are preserved. This file is offered as-is, without any
-#   warranty.
-#serial 8
-AC_DEFUN([AX_CHECK_GNU_MAKE],dnl
-  [AC_PROG_AWK
-  AC_CACHE_CHECK([for GNU make],[_cv_gnu_make_command],[dnl
-    _cv_gnu_make_command="" ;
-dnl Search all the common names for GNU make
-    for a in "$MAKE" make gmake gnumake ; do
-      if test -z "$a" ; then continue ; fi ;
-      if "$a" --version 2> /dev/null | grep GNU 2>&1 > /dev/null ; then
-        _cv_gnu_make_command=$a ;
-        AX_CHECK_GNU_MAKE_HEADLINE=$("$a" --version 2> /dev/null | grep "GNU Make")
-        ax_check_gnu_make_version=$(echo ${AX_CHECK_GNU_MAKE_HEADLINE} | ${AWK} -F " " '{ print $(NF); }')
-        break ;
-      fi
-    done ;])
-dnl If there was a GNU version, then set @ifGNUmake@ to the empty string, '#' otherwise
-  AS_VAR_IF([_cv_gnu_make_command], [""], [AS_VAR_SET([ifGNUmake], ["#"])],   [AS_VAR_SET([ifGNUmake], [""])])
-  AS_VAR_IF([_cv_gnu_make_command], [""], [AS_UNSET(ax_cv_gnu_make_command)], [AS_VAR_SET([ax_cv_gnu_make_command], [${_cv_gnu_make_command}])])
-  AC_SUBST([ifGNUmake])
-])
diff --git a/m4/ax_check_link_flag.m4 b/m4/ax_check_link_flag.m4
deleted file mode 100644
index eb01a6c..0000000
--- a/m4/ax_check_link_flag.m4
+++ /dev/null
@@ -1,74 +0,0 @@
-# ===========================================================================
-#    http://www.gnu.org/software/autoconf-archive/ax_check_link_flag.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_CHECK_LINK_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
-#
-# DESCRIPTION
-#
-#   Check whether the given FLAG works with the linker or gives an error.
-#   (Warnings, however, are ignored)
-#
-#   ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
-#   success/failure.
-#
-#   If EXTRA-FLAGS is defined, it is added to the linker's default flags
-#   when the check is done.  The check is thus made with the flags: "LDFLAGS
-#   EXTRA-FLAGS FLAG".  This can for example be used to force the linker to
-#   issue an error when a bad flag is given.
-#
-#   INPUT gives an alternative input source to AC_LINK_IFELSE.
-#
-#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
-#   macro in sync with AX_CHECK_{PREPROC,COMPILE}_FLAG.
-#
-# LICENSE
-#
-#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
-#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
-#
-#   This program is free software: you can redistribute it and/or modify it
-#   under the terms of the GNU General Public License as published by the
-#   Free Software Foundation, either version 3 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
-#   Public License for more details.
-#
-#   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
-#serial 4
-AC_DEFUN([AX_CHECK_LINK_FLAG],
-[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
-AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_ldflags_$4_$1])dnl
-AC_CACHE_CHECK([whether the linker accepts $1], CACHEVAR, [
-  ax_check_save_flags=$LDFLAGS
-  LDFLAGS="$LDFLAGS $4 $1"
-  AC_LINK_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
-    [AS_VAR_SET(CACHEVAR,[yes])],
-    [AS_VAR_SET(CACHEVAR,[no])])
-  LDFLAGS=$ax_check_save_flags])
-AS_VAR_IF(CACHEVAR,yes,
-  [m4_default([$2], :)],
-  [m4_default([$3], :)])
-AS_VAR_POPDEF([CACHEVAR])dnl
-])dnl AX_CHECK_LINK_FLAGS
diff --git a/m4/ax_code_coverage.m4 b/m4/ax_code_coverage.m4
deleted file mode 100644
index 6c985eb..0000000
--- a/m4/ax_code_coverage.m4
+++ /dev/null
@@ -1,273 +0,0 @@
-# ===========================================================================
-#     http://www.gnu.org/software/autoconf-archive/ax_code_coverage.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_CODE_COVERAGE()
-#
-# DESCRIPTION
-#
-#   Defines CODE_COVERAGE_CPPFLAGS, CODE_COVERAGE_CFLAGS,
-#   CODE_COVERAGE_CXXFLAGS and CODE_COVERAGE_LDFLAGS which should be
-#   included in the CPPFLAGS, CFLAGS CXXFLAGS and LIBS/LDFLAGS variables of
-#   every build target (program or library) which should be built with code
-#   coverage support. Also defines CODE_COVERAGE_RULES which should be
-#   substituted in your Makefile; and $enable_code_coverage which can be
-#   used in subsequent configure output. CODE_COVERAGE_ENABLED is defined
-#   and substituted, and corresponds to the value of the
-#   --enable-code-coverage option, which defaults to being disabled.
-#
-#   Test also for gcov program and create GCOV variable that could be
-#   substituted.
-#
-#   Note that all optimisation flags in CFLAGS must be disabled when code
-#   coverage is enabled.
-#
-#   Usage example:
-#
-#   configure.ac:
-#
-#     AX_CODE_COVERAGE
-#
-#   Makefile.am:
-#
-#     @CODE_COVERAGE_RULES@
-#     my_program_LIBS = ... $(CODE_COVERAGE_LDFLAGS) ...
-#     my_program_CPPFLAGS = ... $(CODE_COVERAGE_CPPFLAGS) ...
-#     my_program_CFLAGS = ... $(CODE_COVERAGE_CFLAGS) ...
-#     my_program_CXXFLAGS = ... $(CODE_COVERAGE_CXXFLAGS) ...
-#
-#   This results in a "check-code-coverage" rule being added to any
-#   Makefile.am which includes "@CODE_COVERAGE_RULES@" (assuming the module
-#   has been configured with --enable-code-coverage). Running `make
-#   check-code-coverage` in that directory will run the module's test suite
-#   (`make check`) and build a code coverage report detailing the code which
-#   was touched, then print the URI for the report.
-#
-#   This code was derived from Makefile.decl in GLib, originally licenced
-#   under LGPLv2.1+.
-#
-# LICENSE
-#
-#   Copyright (c) 2012, 2016 Philip Withnall
-#   Copyright (c) 2012 Xan Lopez
-#   Copyright (c) 2012 Christian Persch
-#   Copyright (c) 2012 Paolo Borelli
-#   Copyright (c) 2012 Dan Winship
-#   Copyright (c) 2015 Bastien ROUCARIES
-#
-#   This library is free software; you can redistribute it and/or modify it
-#   under the terms of the GNU Lesser General Public License as published by
-#   the Free Software Foundation; either version 2.1 of the License, or (at
-#   your option) any later version.
-#
-#   This library is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
-#   General Public License for more details.
-#
-#   You should have received a copy of the GNU Lesser General Public License
-#   along with this program. If not, see <http://www.gnu.org/licenses/>.
-#serial 15
-AC_DEFUN([AX_CODE_COVERAGE],[
-        dnl Check for --enable-code-coverage
-        AC_REQUIRE([AC_PROG_SED])
-        # allow to override gcov location
-        AC_ARG_WITH([gcov],
-          [AS_HELP_STRING([--with-gcov[=GCOV]], [use given GCOV for coverage (GCOV=gcov).])],
-          [_AX_CODE_COVERAGE_GCOV_PROG_WITH=$with_gcov],
-          [_AX_CODE_COVERAGE_GCOV_PROG_WITH=gcov])
-        AC_MSG_CHECKING([whether to build with code coverage support])
-        AC_ARG_ENABLE([code-coverage],
-          AS_HELP_STRING([--enable-code-coverage],
-          [Whether to enable code coverage support]),,
-          enable_code_coverage=no)
-        AM_CONDITIONAL([CODE_COVERAGE_ENABLED], [test x$enable_code_coverage = xyes])
-        AC_SUBST([CODE_COVERAGE_ENABLED], [$enable_code_coverage])
-        AC_MSG_RESULT($enable_code_coverage)
-        AS_IF([ test "$enable_code_coverage" = "yes" ], [
-                # check for gcov
-                AC_CHECK_TOOL([GCOV],
-                  [$_AX_CODE_COVERAGE_GCOV_PROG_WITH],
-                  [:])
-                AS_IF([test "X$GCOV" = "X:"],
-                  [AC_MSG_ERROR([gcov is needed to do coverage])])
-                AC_SUBST([GCOV])
-                dnl Check if gcc is being used
-                AS_IF([ test "$GCC" = "no" ], [
-                        AC_MSG_ERROR([not compiling with gcc, which is required for gcov code coverage])
-                ])
-                # List of supported lcov versions.
-                lcov_version_list="1.6 1.7 1.8 1.9 1.10 1.11 1.12"
-                AC_CHECK_PROG([LCOV], [lcov], [lcov])
-                AC_CHECK_PROG([GENHTML], [genhtml], [genhtml])
-                AS_IF([ test "$LCOV" ], [
-                        AC_CACHE_CHECK([for lcov version], ax_cv_lcov_version, [
-                                ax_cv_lcov_version=invalid
-                                lcov_version=`$LCOV -v 2>/dev/null | $SED -e 's/^.* //'`
-                                for lcov_check_version in $lcov_version_list; do
-                                        if test "$lcov_version" = "$lcov_check_version"; then
-                                                ax_cv_lcov_version="$lcov_check_version (ok)"
-                                        fi
-                                done
-                        ])
-                ], [
-                        lcov_msg="To enable code coverage reporting you must have one of the following lcov versions installed: $lcov_version_list"
-                        AC_MSG_ERROR([$lcov_msg])
-                ])
-                case $ax_cv_lcov_version in
-                        ""|invalid[)]
-                                lcov_msg="You must have one of the following versions of lcov: $lcov_version_list (found: $lcov_version)."
-                                AC_MSG_ERROR([$lcov_msg])
-                                LCOV="exit 0;"
-                        ;;
-                esac
-                AS_IF([ test -z "$GENHTML" ], [
-                        AC_MSG_ERROR([Could not find genhtml from the lcov package])
-                ])
-                dnl Build the code coverage flags
-                CODE_COVERAGE_CPPFLAGS="-DNDEBUG"
-                CODE_COVERAGE_CFLAGS="-O0 -g -fprofile-arcs -ftest-coverage"
-                CODE_COVERAGE_CXXFLAGS="-O0 -g -fprofile-arcs -ftest-coverage"
-                CODE_COVERAGE_LDFLAGS="-lgcov"
-                AC_SUBST([CODE_COVERAGE_CPPFLAGS])
-                AC_SUBST([CODE_COVERAGE_CFLAGS])
-                AC_SUBST([CODE_COVERAGE_CXXFLAGS])
-                AC_SUBST([CODE_COVERAGE_LDFLAGS])
-        ])
-[CODE_COVERAGE_RULES='
-# Code coverage
-#
-# Optional:
-#  - CODE_COVERAGE_DIRECTORY: Top-level directory for code coverage reporting.
-#    Multiple directories may be specified, separated by whitespace.
-#    (Default: $(top_builddir))
-#  - CODE_COVERAGE_OUTPUT_FILE: Filename and path for the .info file generated
-#    by lcov for code coverage. (Default:
-#    $(PACKAGE_NAME)-$(PACKAGE_VERSION)-coverage.info)
-#  - CODE_COVERAGE_OUTPUT_DIRECTORY: Directory for generated code coverage
-#    reports to be created. (Default:
-#    $(PACKAGE_NAME)-$(PACKAGE_VERSION)-coverage)
-#  - CODE_COVERAGE_BRANCH_COVERAGE: Set to 1 to enforce branch coverage,
-#    set to 0 to disable it and leave empty to stay with the default.
-#    (Default: empty)
-#  - CODE_COVERAGE_LCOV_SHOPTS_DEFAULT: Extra options shared between both lcov
-#    instances. (Default: based on $CODE_COVERAGE_BRANCH_COVERAGE)
-#  - CODE_COVERAGE_LCOV_SHOPTS: Extra options to shared between both lcov
-#    instances. (Default: $CODE_COVERAGE_LCOV_SHOPTS_DEFAULT)
-#  - CODE_COVERAGE_LCOV_OPTIONS_GCOVPATH: --gcov-tool pathtogcov
-#  - CODE_COVERAGE_LCOV_OPTIONS_DEFAULT: Extra options to pass to the
-#    collecting lcov instance. (Default: $CODE_COVERAGE_LCOV_OPTIONS_GCOVPATH)
-#  - CODE_COVERAGE_LCOV_OPTIONS: Extra options to pass to the collecting lcov
-#    instance. (Default: $CODE_COVERAGE_LCOV_OPTIONS_DEFAULT)
-#  - CODE_COVERAGE_LCOV_RMOPTS_DEFAULT: Extra options to pass to the filtering
-#    lcov instance. (Default: empty)
-#  - CODE_COVERAGE_LCOV_RMOPTS: Extra options to pass to the filtering lcov
-#    instance. (Default: $CODE_COVERAGE_LCOV_RMOPTS_DEFAULT)
-#  - CODE_COVERAGE_GENHTML_OPTIONS_DEFAULT: Extra options to pass to the
-#    genhtml instance. (Default: based on $CODE_COVERAGE_BRANCH_COVERAGE)
-#  - CODE_COVERAGE_GENHTML_OPTIONS: Extra options to pass to the genhtml
-#    instance. (Default: $CODE_COVERAGE_GENHTML_OPTIONS_DEFAULT)
-#  - CODE_COVERAGE_IGNORE_PATTERN: Extra glob pattern of files to ignore
-#
-# The generated report will be titled using the $(PACKAGE_NAME) and
-# $(PACKAGE_VERSION). In order to add the current git hash to the title,
-# use the git-version-gen script, available online.
-# Optional variables
-CODE_COVERAGE_DIRECTORY ?= $(top_builddir)
-CODE_COVERAGE_OUTPUT_FILE ?= $(PACKAGE_NAME)-$(PACKAGE_VERSION)-coverage.info
-CODE_COVERAGE_OUTPUT_DIRECTORY ?= $(PACKAGE_NAME)-$(PACKAGE_VERSION)-coverage
-CODE_COVERAGE_BRANCH_COVERAGE ?=
-CODE_COVERAGE_LCOV_SHOPTS_DEFAULT ?= $(if $(CODE_COVERAGE_BRANCH_COVERAGE),\
--rc lcov_branch_coverage=$(CODE_COVERAGE_BRANCH_COVERAGE))
-CODE_COVERAGE_LCOV_SHOPTS ?= $(CODE_COVERAGE_LCOV_SHOPTS_DEFAULT)
-CODE_COVERAGE_LCOV_OPTIONS_GCOVPATH ?= --gcov-tool "$(GCOV)"
-CODE_COVERAGE_LCOV_OPTIONS_DEFAULT ?= $(CODE_COVERAGE_LCOV_OPTIONS_GCOVPATH)
-CODE_COVERAGE_LCOV_OPTIONS ?= $(CODE_COVERAGE_LCOV_OPTIONS_DEFAULT)
-CODE_COVERAGE_LCOV_RMOPTS_DEFAULT ?=
-CODE_COVERAGE_LCOV_RMOPTS ?= $(CODE_COVERAGE_LCOV_RMOPTS_DEFAULT)
-CODE_COVERAGE_GENHTML_OPTIONS_DEFAULT ?=\
-$(if $(CODE_COVERAGE_BRANCH_COVERAGE),\
--rc genhtml_branch_coverage=$(CODE_COVERAGE_BRANCH_COVERAGE))
-CODE_COVERAGE_GENHTML_OPTIONS ?= $(CODE_COVERAGE_GENHTML_OPTIONS_DEFAULTS)
-CODE_COVERAGE_IGNORE_PATTERN ?=
-code_coverage_v_lcov_cap = $(code_coverage_v_lcov_cap_$(V))
-code_coverage_v_lcov_cap_ = $(code_coverage_v_lcov_cap_$(AM_DEFAULT_VERBOSITY))
-code_coverage_v_lcov_cap_0 = @echo "  LCOV   --capture"\
- $(CODE_COVERAGE_OUTPUT_FILE);
-code_coverage_v_lcov_ign = $(code_coverage_v_lcov_ign_$(V))
-code_coverage_v_lcov_ign_ = $(code_coverage_v_lcov_ign_$(AM_DEFAULT_VERBOSITY))
-code_coverage_v_lcov_ign_0 = @echo "  LCOV   --remove /tmp/*"\
- $(CODE_COVERAGE_IGNORE_PATTERN);
-code_coverage_v_genhtml = $(code_coverage_v_genhtml_$(V))
-code_coverage_v_genhtml_ = $(code_coverage_v_genhtml_$(AM_DEFAULT_VERBOSITY))
-code_coverage_v_genhtml_0 = @echo "  GEN   " $(CODE_COVERAGE_OUTPUT_DIRECTORY);
-code_coverage_quiet = $(code_coverage_quiet_$(V))
-code_coverage_quiet_ = $(code_coverage_quiet_$(AM_DEFAULT_VERBOSITY))
-code_coverage_quiet_0 = --quiet
-# sanitizes the test-name: replaces with underscores: dashes and dots
-code_coverage_sanitize = $(subst -,_,$(subst .,_,$(1)))
-# Use recursive makes in order to ignore errors during check
-check-code-coverage:
-ifeq ($(CODE_COVERAGE_ENABLED),yes)
-        -$(A''M_V_at)$(MAKE) $(AM_MAKEFLAGS) -k check
-        $(A''M_V_at)$(MAKE) $(AM_MAKEFLAGS) code-coverage-capture
-else
-        @echo "Need to reconfigure with --enable-code-coverage"
-endif
-# Capture code coverage data
-code-coverage-capture: code-coverage-capture-hook
-ifeq ($(CODE_COVERAGE_ENABLED),yes)
-        $(code_coverage_v_lcov_cap)$(LCOV) $(code_coverage_quiet) $(addprefix --directory ,$(CODE_COVERAGE_DIRECTORY)) --capture --output-file "$(CODE_COVERAGE_OUTPUT_FILE).tmp" --test-name "$(call code_coverage_sanitize,$(PACKAGE_NAME)-$(PACKAGE_VERSION))" --no-checksum --compat-libtool $(CODE_COVERAGE_LCOV_SHOPTS) $(CODE_COVERAGE_LCOV_OPTIONS)
-        $(code_coverage_v_lcov_ign)$(LCOV) $(code_coverage_quiet) $(addprefix --directory ,$(CODE_COVERAGE_DIRECTORY)) --remove "$(CODE_COVERAGE_OUTPUT_FILE).tmp" "/tmp/*" $(CODE_COVERAGE_IGNORE_PATTERN) --output-file "$(CODE_COVERAGE_OUTPUT_FILE)" $(CODE_COVERAGE_LCOV_SHOPTS) $(CODE_COVERAGE_LCOV_RMOPTS)
-        -@rm -f $(CODE_COVERAGE_OUTPUT_FILE).tmp
-        $(code_coverage_v_genhtml)LANG=C $(GENHTML) $(code_coverage_quiet) $(addprefix --prefix ,$(CODE_COVERAGE_DIRECTORY)) --output-directory "$(CODE_COVERAGE_OUTPUT_DIRECTORY)" --title "$(PACKAGE_NAME)-$(PACKAGE_VERSION) Code Coverage" --legend --show-details "$(CODE_COVERAGE_OUTPUT_FILE)" $(CODE_COVERAGE_GENHTML_OPTIONS)
-        @echo "file://$(abs_builddir)/$(CODE_COVERAGE_OUTPUT_DIRECTORY)/index.html"
-else
-        @echo "Need to reconfigure with --enable-code-coverage"
-endif
-# Hook rule executed before code-coverage-capture, overridable by the user
-code-coverage-capture-hook:
-ifeq ($(CODE_COVERAGE_ENABLED),yes)
-clean: code-coverage-clean
-code-coverage-clean:
-        -$(LCOV) --directory $(top_builddir) -z
-        -rm -rf $(CODE_COVERAGE_OUTPUT_FILE) $(CODE_COVERAGE_OUTPUT_FILE).tmp $(CODE_COVERAGE_OUTPUT_DIRECTORY)
-        -find . -name "*.gcda" -o -name "*.gcov" -delete
-endif
-GITIGNOREFILES ?=
-GITIGNOREFILES += $(CODE_COVERAGE_OUTPUT_FILE) $(CODE_COVERAGE_OUTPUT_DIRECTORY)
-A''M_DISTCHECK_CONFIGURE_FLAGS ?=
-A''M_DISTCHECK_CONFIGURE_FLAGS += --disable-code-coverage
-.PHONY: check-code-coverage code-coverage-capture code-coverage-capture-hook code-coverage-clean
-']
-        AC_SUBST([CODE_COVERAGE_RULES])
-        m4_ifdef([_AM_SUBST_NOTMAKE], [_AM_SUBST_NOTMAKE([CODE_COVERAGE_RULES])])
-])
diff --git a/m4/ax_configure_args.m4 b/m4/ax_configure_args.m4
deleted file mode 100644
index 0726b1b..0000000
--- a/m4/ax_configure_args.m4
+++ /dev/null
@@ -1,70 +0,0 @@
-# ===========================================================================
-#     http://www.gnu.org/software/autoconf-archive/ax_configure_args.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_CONFIGURE_ARGS
-#
-# DESCRIPTION
-#
-#   Helper macro for AX_ENABLE_BUILDDIR.
-#
-#   The traditional way of starting a subdir-configure is running the script
-#   with ${1+"$@"} but since autoconf 2.60 this is broken. Instead we have
-#   to rely on eval'ing $ac_configure_args however some old autoconf
-#   versions do not provide that. To ensure maximum portability of autoconf
-#   extension macros this helper can be AC_REQUIRE'd so that
-#   $ac_configure_args will alsways be present.
-#
-#   Sadly, the traditional "exec $SHELL" of the enable_builddir macros is
-#   spoiled now and must be replaced by "eval + exit $?".
-#
-#   Example:
-#
-#     AC_DEFUN([AX_ENABLE_SUBDIR],[dnl
-#       AC_REQUIRE([AX_CONFIGURE_ARGS])dnl
-#       eval $SHELL $ac_configure_args || exit $?
-#       ...])
-#
-# LICENSE
-#
-#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
-#
-#   This program is free software; you can redistribute it and/or modify it
-#   under the terms of the GNU General Public License as published by the
-#   Free Software Foundation; either version 3 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
-#   Public License for more details.
-#
-#   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
-#serial 9
-AC_DEFUN([AX_CONFIGURE_ARGS],[
-   # [$]@ is unsable in 2.60+ but earlier autoconf had no ac_configure_args
-   if test "${ac_configure_args+set}" != "set" ; then
-      ac_configure_args=
-      for ac_arg in ${1+"[$]@"}; do
-         ac_configure_args="$ac_configure_args '$ac_arg'"
-      done
-   fi
-])
diff --git a/m4/ax_enable_builddir.m4 b/m4/ax_enable_builddir.m4
deleted file mode 100644
index 5f4ba32..0000000
--- a/m4/ax_enable_builddir.m4
+++ /dev/null
@@ -1,302 +0,0 @@
-# ===========================================================================
-#    http://www.gnu.org/software/autoconf-archive/ax_enable_builddir.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_ENABLE_BUILDDIR [(dirstring-or-command [,Makefile.mk [,-all]])]
-#
-# DESCRIPTION
-#
-#   If the current configure was run within the srcdir then we move all
-#   configure-files into a subdir and let the configure steps continue
-#   there. We provide an option --disable-builddir to suppress the move into
-#   a separate builddir.
-#
-#   Defaults:
-#
-#     $1 = $host (overridden with $HOST)
-#     $2 = Makefile.mk
-#     $3 = -all
-#
-#   This macro must be called before AM_INIT_AUTOMAKE. It creates a default
-#   toplevel srcdir Makefile from the information found in the created
-#   toplevel builddir Makefile. It just copies the variables and
-#   rule-targets, each extended with a default rule-execution that recurses
-#   into the build directory of the current "HOST". You can override the
-#   auto-dection through `config.guess` and build-time of course, as in
-#
-#     make HOST=i386-mingw-cross
-#
-#   which can of course set at configure time as well using
-#
-#     configure --host=i386-mingw-cross
-#
-#   After the default has been created, additional rules can be appended
-#   that will not just recurse into the subdirectories and only ever exist
-#   in the srcdir toplevel makefile - these parts are read from the $2 =
-#   Makefile.mk file
-#
-#   The automatic rules are usually scanning the toplevel Makefile for lines
-#   like '#### $host |$builddir' to recognize the place where to recurse
-#   into. Usually, the last one is the only one used. However, almost all
-#   targets have an additional "*-all" rule which makes the script to
-#   recurse into _all_ variants of the current HOST (!!) setting. The "-all"
-#   suffix can be overriden for the macro as well.
-#
-#   a special rule is only given for things like "dist" that will copy the
-#   tarball from the builddir to the sourcedir (or $(PUB)) for reason of
-#   convenience.
-#
-# LICENSE
-#
-#   Copyright (c) 2009 Guido U. Draheim <guidod@gmx.de>
-#   Copyright (c) 2009 Alan Jenkins <alan-jenkins@tuffmail.co.uk>
-#
-#   This program is free software; you can redistribute it and/or modify it
-#   under the terms of the GNU General Public License as published by the
-#   Free Software Foundation; either version 3 of the License, or (at your
-#   option) any later version.
-#
-#   This program is distributed in the hope that it will be useful, but
-#   WITHOUT ANY WARRANTY; without even the implied warranty of
-#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
-#   Public License for more details.
-#
-#   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
-#
-#   As a special exception, the respective Autoconf Macro's copyright owner
-#   gives unlimited permission to copy, distribute and modify the configure
-#   scripts that are the output of Autoconf when processing the Macro. You
-#   need not follow the terms of the GNU General Public License when using
-#   or distributing such scripts, even though portions of the text of the
-#   Macro appear in them. The GNU General Public License (GPL) does govern
-#   all other use of the material that constitutes the Autoconf Macro.
-#
-#   This special exception to the GPL applies to versions of the Autoconf
-#   Macro released by the Autoconf Archive. When you make and distribute a
-#   modified version of the Autoconf Macro, you may extend this special
-#   exception to the GPL to apply to your modified version as well.
-#serial 25
-AC_DEFUN([AX_ENABLE_BUILDDIR],[
-AC_REQUIRE([AC_CANONICAL_HOST])[]dnl
-AC_REQUIRE([AC_CANONICAL_TARGET])[]dnl
-AC_REQUIRE([AX_CONFIGURE_ARGS])[]dnl
-AC_REQUIRE([AM_AUX_DIR_EXPAND])[]dnl
-AC_BEFORE([$0],[AM_INIT_AUTOMAKE])dnl
-AS_VAR_PUSHDEF([SUB],[ax_enable_builddir])dnl
-AS_VAR_PUSHDEF([AUX],[ax_enable_builddir_auxdir])dnl
-AS_VAR_PUSHDEF([SED],[ax_enable_builddir_sed])dnl
-SUB="."
-AC_ARG_ENABLE([builddir], AS_HELP_STRING(
-  [--disable-builddir],[disable automatic build in subdir of sources])
-  ,[SUB="$enableval"], [SUB="auto"])
-if test ".$ac_srcdir_defaulted" != ".no" ; then
-if test ".$srcdir" = ".." ; then
-  if test -f config.status ; then
-    AC_MSG_NOTICE(toplevel srcdir already configured... skipping subdir build)
-  else
-    test ".$SUB" = "."  && SUB="."
-    test ".$SUB" = ".no"  && SUB="."
-    test ".$TARGET" = "." && TARGET="$target"
-    test ".$SUB" = ".auto" && SUB="m4_ifval([$1], [$1],[$TARGET])"
-    if test ".$SUB" != ".." ; then    # we know where to go and
-      AS_MKDIR_P([$SUB])
-      echo __.$SUB.__ > $SUB/conftest.tmp
-      cd $SUB
-      if grep __.$SUB.__ conftest.tmp >/dev/null 2>/dev/null ; then
-        rm conftest.tmp
-        AC_MSG_RESULT([continue configure in default builddir "./$SUB"])
-      else
-        AC_MSG_ERROR([could not change to default builddir "./$SUB"])
-      fi
-      srcdir=`echo "$SUB" |
-              sed -e 's,^\./,,;s,[[^/]]$,&/,;s,[[^/]]*/,../,g;s,[[/]]$,,;'`
-      # going to restart from subdirectory location
-      test -f $srcdir/config.log   && mv $srcdir/config.log   .
-      test -f $srcdir/confdefs.h   && mv $srcdir/confdefs.h   .
-      test -f $srcdir/conftest.log && mv $srcdir/conftest.log .
-      test -f $srcdir/$cache_file  && mv $srcdir/$cache_file  .
-      AC_MSG_RESULT(....exec $SHELL $srcdir/[$]0 "--srcdir=$srcdir" "--enable-builddir=$SUB" ${1+"[$]@"})
-      case "[$]0" in # restart
-       [[\\/]]* | ?:[[\\/]]*) # Asbolute name
-         eval $SHELL "'[$]0'" "'--srcdir=$srcdir'" "'--enable-builddir=$SUB'" $ac_configure_args ;;
-       *) eval $SHELL "'$srcdir/[$]0'" "'--srcdir=$srcdir'" "'--enable-builddir=$SUB'" $ac_configure_args ;;
-      esac ; exit $?
-    fi
-  fi
-fi fi
-test ".$SUB" = ".auto" && SUB="."
-dnl ac_path_prog uses "set dummy" to override $@ which would defeat the "exec"
-AC_PATH_PROG(SED,gsed sed, sed)
-AUX="$am_aux_dir"
-AS_VAR_POPDEF([SED])dnl
-AS_VAR_POPDEF([AUX])dnl
-AS_VAR_POPDEF([SUB])dnl
-AC_CONFIG_COMMANDS([buildir],[dnl .............. config.status ..............
-AS_VAR_PUSHDEF([SUB],[ax_enable_builddir])dnl
-AS_VAR_PUSHDEF([TOP],[top_srcdir])dnl
-AS_VAR_PUSHDEF([SRC],[ac_top_srcdir])dnl
-AS_VAR_PUSHDEF([AUX],[ax_enable_builddir_auxdir])dnl
-AS_VAR_PUSHDEF([SED],[ax_enable_builddir_sed])dnl
-pushdef([END],[Makefile.mk])dnl
-pushdef([_ALL],[ifelse([$3],,[-all],[$3])])dnl
-  SRC="$ax_enable_builddir_srcdir"
-  if test ".$SUB" = ".." ; then
-    if test -f "$TOP/Makefile" ; then
-      AC_MSG_NOTICE([skipping TOP/Makefile - left untouched])
-    else
-      AC_MSG_NOTICE([skipping TOP/Makefile - not created])
-    fi
-  else
-    if test -f "$SRC/Makefile" ; then
-      a=`grep "^VERSION " "$SRC/Makefile"` ; b=`grep "^VERSION " Makefile`
-      test "$a" != "$b" && rm "$SRC/Makefile"
-    fi
-    if test -f "$SRC/Makefile" ; then
-        echo "$SRC/Makefile : $SRC/Makefile.in" > $tmp/conftemp.mk
-        echo "  []@ echo 'REMOVED,,,' >\$[]@" >> $tmp/conftemp.mk
-      eval "${MAKE-make} -f $tmp/conftemp.mk 2>/dev/null >/dev/null"
-      if grep '^REMOVED,,,' "$SRC/Makefile" >/dev/null
-      then rm $SRC/Makefile ; fi
-      cp $tmp/conftemp.mk $SRC/makefiles.mk~      ## DEBUGGING
-    fi
-    if test ! -f "$SRC/Makefile" ; then
-      AC_MSG_NOTICE([create TOP/Makefile guessed from local Makefile])
-      x='`' ; cat >$tmp/conftemp.sed <<_EOF
-/^\$/n
-x
-/^\$/bS
-x
-/\\\\\$/{H;d;}
-{H;s/.*//;x;}
-bM
-:S
-x
-/\\\\\$/{h;d;}
-{h;s/.*//;x;}
-:M
-s/\\(\\n\\)     /\\1 /g
-/^      /d
-/^[[     ]]*[[\\#]]/d
-/^VPATH *=/d
-s/^srcdir *=.*/srcdir = ./
-s/^top_srcdir *=.*/top_srcdir = ./
-/[[:=]]/!d
-/^\\./d
-dnl Now handle rules (i.e. lines containing ":" but not " = ").
-/ = /b
-/ .= /b
-/:/!b
-s/:.*/:/
-s/ /  /g
-s/ \\([[a-z]][[a-z-]]*[[a-zA-Z0-9]]\\)\\([[ :]]\\)/ \\1 \\1[]_ALL\\2/g
-s/^\\([[a-z]][[a-z-]]*[[a-zA-Z0-9]]\\)\\([[ :]]\\)/\\1 \\1[]_ALL\\2/
-s/  / /g
-/^all all[]_ALL[[ :]]/i\\
-all-configured : all[]_ALL
-dnl dist-all exists... and would make for dist-all-all
-s/ [[a-zA-Z0-9-]]*[]_ALL [[a-zA-Z0-9-]]*[]_ALL[]_ALL//g
-/[]_ALL[]_ALL/d
-a\\
-        @ HOST="\$(HOST)\" \\\\\\
-        ; test ".\$\$HOST" = "." && HOST=$x sh $AUX/config.guess $x \\\\\\
-        ; BUILD=$x grep "^#### \$\$HOST " Makefile | sed -e 's/.*|//' $x \\\\\\
-        ; use=$x basename "\$\@" _ALL $x; n=$x echo \$\$BUILD | wc -w $x \\\\\\
-        ; echo "MAKE \$\$HOST : \$\$n * \$\@"; if test "\$\$n" -eq "0" ; then : \\\\\\
-        ; BUILD=$x grep "^####.*|" Makefile |tail -1| sed -e 's/.*|//' $x ; fi \\\\\\
-        ; test ".\$\$BUILD" = "." && BUILD="." \\\\\\
-        ; test "\$\$use" = "\$\@" && BUILD=$x echo "\$\$BUILD" | tail -1 $x \\\\\\
-        ; for i in \$\$BUILD ; do test ".\$\$i" = "." && continue \\\\\\
-        ; (cd "\$\$i" && test ! -f configure && \$(MAKE) \$\$use) || exit; done
-dnl special rule add-on: "dist" copies the tarball to $(PUB). (source tree)
-/dist[]_ALL *:/a\\
-        @ HOST="\$(HOST)\" \\\\\\
-        ; test ".\$\$HOST" = "." && HOST=$x sh $AUX/config.guess $x \\\\\\
-        ; BUILD=$x grep "^#### \$\$HOST " Makefile | sed -e 's/.*|//' $x \\\\\\
-        ; found=$x echo \$\$BUILD | wc -w $x \\\\\\
-        ; echo "MAKE \$\$HOST : \$\$found \$(PACKAGE)-\$(VERSION).tar.*" \\\\\\
-        ; if test "\$\$found" -eq "0" ; then : \\\\\\
-        ; BUILD=$x grep "^#### .*|" Makefile |tail -1| sed -e 's/.*|//' $x \\\\\\
-        ; fi ; for i in \$\$BUILD ; do test ".\$\$i" = "." && continue \\\\\\
-        ; for f in \$\$i/\$(PACKAGE)-\$(VERSION).tar.* \\\\\\
-        ; do test -f "\$\$f" && mv "\$\$f" \$(PUB). ; done ; break ; done
-dnl special rule add-on: "dist-foo" copies all the archives to $(PUB). (source tree)
-/dist-[[a-zA-Z0-9]]*[]_ALL *:/a\\
-        @ HOST="\$(HOST)\" \\\\\\
-        ; test ".\$\$HOST" = "." && HOST=$x sh ./config.guess $x \\\\\\
-        ; BUILD=$x grep "^#### \$\$HOST " Makefile | sed -e 's/.*|//' $x \\\\\\
-        ; found=$x echo \$\$BUILD | wc -w $x \\\\\\
-        ; echo "MAKE \$\$HOST : \$\$found \$(PACKAGE)-\$(VERSION).*" \\\\\\
-        ; if test "\$\$found" -eq "0" ; then : \\\\\\
-        ; BUILD=$x grep "^#### .*|" Makefile |tail -1| sed -e 's/.*|//' $x \\\\\\
-        ; fi ; for i in \$\$BUILD ; do test ".\$\$i" = "." && continue \\\\\\
-        ; for f in \$\$i/\$(PACKAGE)-\$(VERSION).* \\\\\\
-        ; do test -f "\$\$f" && mv "\$\$f" \$(PUB). ; done ; break ; done
-dnl special rule add-on: "distclean" removes all local builddirs completely
-/distclean[]_ALL *:/a\\
-        @ HOST="\$(HOST)\" \\\\\\
-        ; test ".\$\$HOST" = "." && HOST=$x sh $AUX/config.guess $x \\\\\\
-        ; BUILD=$x grep "^#### .*|" Makefile | sed -e 's/.*|//' $x \\\\\\
-        ; use=$x basename "\$\@" _ALL $x; n=$x echo \$\$BUILD | wc -w $x \\\\\\
-        ; echo "MAKE \$\$HOST : \$\$n * \$\@ (all local builds)" \\\\\\
-        ; test ".\$\$BUILD" = "." && BUILD="." \\\\\\
-        ; for i in \$\$BUILD ; do test ".\$\$i" = "." && continue \\\\\\
-        ; echo "# rm -r \$\$i"; done ; echo "# (sleep 3)" ; sleep 3 \\\\\\
-        ; for i in \$\$BUILD ; do test ".\$\$i" = "." && continue \\\\\\
-        ; echo "\$\$i" | grep "^/" > /dev/null && continue \\\\\\
-        ; echo "\$\$i" | grep "^../" > /dev/null && continue \\\\\\
-        ; echo "rm -r \$\$i"; (rm -r "\$\$i") ; done ; rm Makefile
-_EOF
-      cp "$tmp/conftemp.sed" "$SRC/makefile.sed~"            ## DEBUGGING
-      $SED -f $tmp/conftemp.sed Makefile >$SRC/Makefile
-      if test -f "$SRC/m4_ifval([$2],[$2],[END])" ; then
-        AC_MSG_NOTICE([extend TOP/Makefile with TOP/m4_ifval([$2],[$2],[END])])
-        cat $SRC/END >>$SRC/Makefile
-      fi ; xxxx="####"
-      echo "$xxxx CONFIGURATIONS FOR TOPLEVEL MAKEFILE: " >>$SRC/Makefile
-      # sanity check
-      if grep '^; echo "MAKE ' $SRC/Makefile >/dev/null ; then
-        AC_MSG_NOTICE([buggy sed found - it deletes tab in "a" text parts])
-        $SED -e '/^@ HOST=/s/^/ /' -e '/^; /s/^/        /' $SRC/Makefile \
-          >$SRC/Makefile~
-        (test -s $SRC/Makefile~ && mv $SRC/Makefile~ $SRC/Makefile) 2>/dev/null
-      fi
-    else
-      xxxx="\\#\\#\\#\\#"
-      # echo "/^$xxxx *$ax_enable_builddir_host /d" >$tmp/conftemp.sed
-      echo "s!^$xxxx [[^|]]* | *$SUB *\$!$xxxx ...... $SUB!" >$tmp/conftemp.sed
-      $SED -f "$tmp/conftemp.sed" "$SRC/Makefile" >$tmp/mkfile.tmp
-        cp "$tmp/conftemp.sed" "$SRC/makefiles.sed~"         ## DEBUGGING
-        cp "$tmp/mkfile.tmp"   "$SRC/makefiles.out~"         ## DEBUGGING
-      if cmp -s "$SRC/Makefile" "$tmp/mkfile.tmp" 2>/dev/null ; then
-        AC_MSG_NOTICE([keeping TOP/Makefile from earlier configure])
-        rm "$tmp/mkfile.tmp"
-      else
-        AC_MSG_NOTICE([reusing TOP/Makefile from earlier configure])
-        mv "$tmp/mkfile.tmp" "$SRC/Makefile"
-      fi
-    fi
-    AC_MSG_NOTICE([build in $SUB (HOST=$ax_enable_builddir_host)])
-    xxxx="####"
-    echo "$xxxx" "$ax_enable_builddir_host" "|$SUB" >>$SRC/Makefile
-  fi
-popdef([END])dnl
-AS_VAR_POPDEF([SED])dnl
-AS_VAR_POPDEF([AUX])dnl
-AS_VAR_POPDEF([SRC])dnl
-AS_VAR_POPDEF([TOP])dnl
-AS_VAR_POPDEF([SUB])dnl
-],[dnl
-ax_enable_builddir_srcdir="$srcdir"                    # $srcdir
-ax_enable_builddir_host="$HOST"                        # $HOST / $host
-ax_enable_builddir_version="$VERSION"                  # $VERSION
-ax_enable_builddir_package="$PACKAGE"                  # $PACKAGE
-ax_enable_builddir_auxdir="$ax_enable_builddir_auxdir" # $AUX
-ax_enable_builddir_sed="$ax_enable_builddir_sed"       # $SED
-ax_enable_builddir="$ax_enable_builddir"               # $SUB
-])dnl
-])
diff --git a/m4/ax_extend_srcdir.m4 b/m4/ax_extend_srcdir.m4
deleted file mode 100644
index 40f3787..0000000
--- a/m4/ax_extend_srcdir.m4
+++ /dev/null
@@ -1,86 +0,0 @@
-# ===========================================================================
-#     http://www.gnu.org/software/autoconf-archive/ax_extend_srcdir.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_EXTEND_SRCDIR
-#
-# DESCRIPTION
-#
-#   The AX_EXTEND_SRCDIR macro extends $srcdir by one path component.
-#
-#   As an example, when working in /home/michael/i3-4.12/build and calling
-#   ../configure, your $srcdir is "..". After calling AX_EXTEND_SRCDIR,
-#   $srcdir will be set to "../../i3-4.12".
-#
-#   The result of extending $srcdir is that filenames (e.g. in the output of
-#   the "backtrace" gdb command) will include one more path component of the
-#   absolute source path. The additional path component makes it easy for
-#   users to recognize which files belong to the PACKAGE, and -- provided a
-#   dist tarball was unpacked -- which version of PACKAGE was used.
-#
-#   As an example, in "backtrace", you will see:
-#
-#     #0  main (argc=1, argv=0x7fffffff1fc8) at ../../i3-4.12/src/main.c:187
-#
-#   instead of:
-#
-#     #0  main (argc=1, argv=0x7fffffff1fc8) at ../src/main.c:187
-#
-#   In case your code uses the __FILE__ preprocessor directive to refer to
-#   the filename of the current source file (e.g. in debug messages), using
-#   the extended path might be undesirable. For this purpose,
-#   AX_EXTEND_SRCDIR defines the output variable AX_EXTEND_SRCDIR_CPPFLAGS,
-#   which can be added to AM_CPPFLAGS in Makefile.am in order to define the
-#   preprocessor directive STRIPPED__FILE__. As an example, when compiling
-#   the file "../../i3-4.12/src/main.c", STRIPPED__FILE__ evaluates to
-#   "main.c".
-#
-#   There are some caveats: When $srcdir is "." (i.e. when ./configure was
-#   called instead of ../configure in a separate build directory),
-#   AX_EXTEND_SRCDIR will still extend $srcdir, but the intended effect will
-#   not be achieved because of the way automake specifies file paths:
-#   automake defines COMPILE to use "`test -f '$source' || echo
-#   '\$(srcdir)/'`$source" in order to prefer files in the current directory
-#   over specifying $srcdir explicitly.
-#
-#   The AX_EXTEND_SRCDIR author is not aware of any way to influence this
-#   automake behavior. Patches very welcome.
-#
-#   To work around this issue, you can use AX_ENABLE_BUILDDIR i.e. by adding
-#   the following code to configure.ac:
-#
-#     AX_ENABLE_BUILDDIR
-#     dnl ...
-#     AX_EXTEND_SRCDIR
-#
-#   Then also add this bit to Makefile.am (if you wish to use
-#   STRIPPED__FILE__ in your code):
-#
-#     AM_CPPFLAGS = @AX_EXTEND_SRCDIR_CPPFLAGS@
-#
-# LICENSE
-#
-#   Copyright (c) 2016 Michael Stapelberg <michael@i3wm.org>
-#
-#   Copying and distribution of this file, with or without modification, are
-#   permitted in any medium without royalty provided the copyright notice
-#   and this notice are preserved.  This file is offered as-is, without any
-#   warranty.
-#serial 3
-AC_DEFUN([AX_EXTEND_SRCDIR],
-[dnl
-AS_CASE([$srcdir],
-  [.|.*|/*],
-  [
-    # pwd -P is specified in IEEE 1003.1 from 2004
-    as_dir=`cd "$srcdir" && pwd -P`
-    as_base=`AS_BASENAME([$as_dir])`
-    srcdir=${srcdir}/../${as_base}
-    AC_SUBST([AX_EXTEND_SRCDIR_CPPFLAGS], ["-DSTRIPPED__FILE__=AS_ESCAPE([\"$$(basename $<)\"])"])
-  ])
-])dnl AX_EXTEND_SRCDIR
diff --git a/m4/ax_require_defined.m4 b/m4/ax_require_defined.m4
deleted file mode 100644
index cae1111..0000000
--- a/m4/ax_require_defined.m4
+++ /dev/null
@@ -1,37 +0,0 @@
-# ===========================================================================
-#    http://www.gnu.org/software/autoconf-archive/ax_require_defined.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_REQUIRE_DEFINED(MACRO)
-#
-# DESCRIPTION
-#
-#   AX_REQUIRE_DEFINED is a simple helper for making sure other macros have
-#   been defined and thus are available for use.  This avoids random issues
-#   where a macro isn't expanded.  Instead the configure script emits a
-#   non-fatal:
-#
-#     ./configure: line 1673: AX_CFLAGS_WARN_ALL: command not found
-#
-#   It's like AC_REQUIRE except it doesn't expand the required macro.
-#
-#   Here's an example:
-#
-#     AX_REQUIRE_DEFINED([AX_CHECK_LINK_FLAG])
-#
-# LICENSE
-#
-#   Copyright (c) 2014 Mike Frysinger <vapier@gentoo.org>
-#
-#   Copying and distribution of this file, with or without modification, are
-#   permitted in any medium without royalty provided the copyright notice
-#   and this notice are preserved. This file is offered as-is, without any
-#   warranty.
-#serial 1
-AC_DEFUN([AX_REQUIRE_DEFINED], [dnl
-  m4_ifndef([$1], [m4_fatal([macro ]$1[ is not defined; is a m4 file missing?])])
-])dnl AX_REQUIRE_DEFINED
diff --git a/m4/ax_sanitizers.m4 b/m4/ax_sanitizers.m4
deleted file mode 100644
index 836d4af..0000000
--- a/m4/ax_sanitizers.m4
+++ /dev/null
@@ -1,130 +0,0 @@
-# ===========================================================================
-#      http://www.gnu.org/software/autoconf-archive/ax_sanitizers.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_SANITIZERS([SANITIZERS], [ENABLED-BY-DEFAULT], [ACTION-SUCCESS])
-#
-# DESCRIPTION
-#
-#   Offers users to enable one or more sanitizers (see
-#   https://github.com/google/sanitizers) with the corresponding
-#   --enable-<sanitizer>-sanitizer option.
-#
-#   SANITIZERS is a whitespace-separated list of sanitizers to offer via
-#   --enable-<sanitizer>-sanitizer options, e.g. "address memory" for the
-#   address sanitizer and the memory sanitizer. If SANITIZERS is not specified,
-#   all known sanitizers to AX_SANITIZERS will be offered, which at the time of
-#   writing are "address memory undefined".
-#   NOTE that SANITIZERS is expanded at autoconf time, not at configure time,
-#   i.e. you cannot use shell variables in SANITIZERS.
-#
-#   ENABLED-BY-DEFAULT is a whitespace-separated list of sanitizers which
-#   should be enabled by default, e.g. "memory undefined". Note that not all
-#   sanitizers can be combined, e.g. memory sanitizer cannot be enabled when
-#   address sanitizer is already enabled.
-#   Set ENABLED-BY-DEFAULT to a single whitespace in order to disable all
-#   sanitizers by default.
-#   ENABLED-BY-DEFAULT is expanded at configure time, so you can use shell
-#   variables.
-#
-#   ACTION-SUCCESS allows to specify shell commands to execute on success, i.e.
-#   when one of the sanitizers was successfully enabled. This is a good place
-#   to call AC_DEFINE for any precompiler constants you might need to make your
-#   code play nice with sanitizers.
-#
-#   The variable ax_enabled_sanitizers contains a whitespace-separated list of
-#   all enabled sanitizers, so that you can print them at the end of configure,
-#   if you wish.
-#
-#   The additional --enable-sanitizers option allows users to enable/disable
-#   all sanitizers, effectively overriding ENABLED-BY-DEFAULT.
-#
-# EXAMPLES
-#
-#   AX_SANITIZERS([address])
-#     dnl offer users to enable address sanitizer via --enable-address-sanitizer
-#
-#   is_debug_build=…
-#   if test "x$is_debug_build" = "xyes"; then
-#     default_sanitizers="address memory"
-#   else
-#     default_sanitizers=
-#   fi
-#   AX_SANITIZERS([address memory], [$default_sanitizers])
-#     dnl enable address sanitizer and memory sanitizer by default for debug
-#     dnl builds, e.g. when building from git instead of a dist tarball.
-#
-#   AX_SANITIZERS(, , [
-#     AC_DEFINE([SANITIZERS_ENABLED],
-#               [],
-#               [At least one sanitizer was enabled])])
-#     dnl enable all sanitizers known to AX_SANITIZERS by default and set the
-#     dnl SANITIZERS_ENABLED precompiler constant.
-#
-#   AX_SANITIZERS(, [ ])
-#     dnl provide all sanitizers, but enable none by default.
-#
-# LICENSE
-#
-#   Copyright (c) 2016 Michael Stapelberg <michael@i3wm.org>
-#
-#   Copying and distribution of this file, with or without modification,
-#   are permitted in any medium without royalty provided the copyright
-#   notice and this notice are preserved.  This file is offered as-is,
-#   without any warranty.
-AC_DEFUN([AX_SANITIZERS],
-[AX_REQUIRE_DEFINED([AX_CHECK_COMPILE_FLAG])
-AX_REQUIRE_DEFINED([AX_CHECK_LINK_FLAG])
-AX_REQUIRE_DEFINED([AX_APPEND_FLAG])
-AC_ARG_ENABLE(sanitizers,
-  AS_HELP_STRING(
-    [--enable-sanitizers],
-    [enable all known sanitizers]),
-  [ax_sanitizers_default=$enableval],
-  [ax_sanitizers_default=])
-ax_enabled_sanitizers=
-m4_foreach_w([mysan], m4_default($1, [address memory undefined]), [
-  dnl If ax_sanitizers_default is unset, i.e. the user neither explicitly
-  dnl enabled nor explicitly disabled all sanitizers, we get the default value
-  dnl for this sanitizer based on whether it is listed in ENABLED-BY-DEFAULT.
-  AS_IF([test "x$ax_sanitizers_default" = "x"], [dnl
-          ax_sanitizer_default=
-          for mycheck in m4_default([$2], [address memory undefined]); do
-            AS_IF([test "x$mycheck" = "x[]mysan"], [ax_sanitizer_default=yes])
-          done
-          AS_IF([test "x$ax_sanitizer_default" = "x"], [ax_sanitizer_default=no])
-        ],
-        [ax_sanitizer_default=$ax_sanitizers_default])
-  AC_ARG_ENABLE(mysan[]-sanitizer,
-    AS_HELP_STRING(
-      [--enable-[]mysan[]-sanitizer],
-      [enable -fsanitize=mysan]),
-    [ax_sanitizer_enabled=$enableval],
-    [ax_sanitizer_enabled=$ax_sanitizer_default])
-AS_IF([test "x$ax_sanitizer_enabled" = "xyes"], [
-dnl Not using AX_APPEND_COMPILE_FLAGS and AX_APPEND_LINK_FLAGS because they
-dnl lack the ability to specify ACTION-SUCCESS.
-  AX_CHECK_COMPILE_FLAG([-fsanitize=[]mysan], [
-    AX_CHECK_LINK_FLAG([-fsanitize=[]mysan], [
-      AX_APPEND_FLAG([-fsanitize=[]mysan], [])
-dnl If and only if libtool is being used, LDFLAGS needs to contain -Wc,-fsanitize=….
-dnl See e.g. https://sources.debian.net/src/systemd/231-7/configure.ac/?hl=128#L135
-dnl TODO: how can recognize that situation and add -Wc,?
-      AX_APPEND_FLAG([-fsanitize=[]mysan], [LDFLAGS])
-dnl TODO: add -fPIE -pie for memory
-      # -fno-omit-frame-pointer results in nicer stack traces in error
-      # messages, see http://clang.llvm.org/docs/AddressSanitizer.html#usage
-      AX_CHECK_COMPILE_FLAG([-fno-omit-frame-pointer], [
-        AX_APPEND_FLAG([-fno-omit-frame-pointer], [])])
-dnl TODO: at least for clang, we should specify exactly -O1, not -O2 or -O0, so that performance is reasonable but stacktraces are not tampered with (due to inlining), see http://clang.llvm.org/docs/AddressSanitizer.html#usage
-      m4_default([$3], :)
-      ax_enabled_sanitizers="[]mysan $ax_enabled_sanitizers"
-    ])
-  ])
-])
-])dnl
-])dnl AX_SANITIZERS
diff --git a/meson.build b/meson.build
new file mode 100644
index 0000000..c3b4dc8
--- /dev/null
+++ b/meson.build
@@ -0,0 +1,130 @@
+# -*- mode: meson -*-
+# Style objective: be consistent with what mesonbuild.com documents/uses, and/or
+# the meson book: https://meson-manual.com/
+project(
+  'i3lock-extended',
+  'c',
+  version: '2.2.14',
+  default_options: [
+    'c_std=c11',
+    'warning_level=1',  # enable all warnings (-Wall)
+  ],
+  # Ubuntu 18.04 (supported until 2023) has meson 0.45.
+  # We can revisit our minimum supported meson version
+  # if it turns out to be too hard to maintain.
+  meson_version: '>=0.45.0',
+)
+cc = meson.get_compiler('c')
+add_project_arguments(cc.get_supported_arguments(['-Wunused-value']), language: 'c')
+if meson.version().version_compare('>=0.48.0')
+  # https://github.com/mesonbuild/meson/issues/2166#issuecomment-629696911
+  meson.add_dist_script('meson/meson-dist-script')
+else
+  message('meson <0.48.0 detected, dist tarballs will not be filtered')
+endif
+################################################################################
+# Version handling
+################################################################################
+cdata = configuration_data()
+version_array = meson.project_version().split('.')
+cdata.set_quoted('I3LOCK_VERSION', meson.project_version())
+cdata.set_quoted('SYSCONFDIR', join_paths(get_option('prefix'), get_option('sysconfdir')))
+if get_option('b_sanitize').split(',').contains('address')
+  cdata.set('I3LOCK_ASAN_ENABLED', 1)
+endif
+cdata.set('HAVE_STRNDUP', cc.has_function('strndup'))
+cdata.set('HAVE_MKDIRP', cc.has_function('mkdirp'))
+config_h = configure_file(
+  output: 'config.h',
+  configuration: cdata,
+)
+config_h = declare_dependency(sources: config_h)
+################################################################################
+# manpages
+################################################################################
+install_man('i3lock-extended.1')
+# Required for e.g. struct ucred to be defined as per unix(7).
+add_project_arguments('-D_GNU_SOURCE', language: 'c')
+add_project_arguments('-DEXTRAS', language: 'c')
+# https://mesonbuild.com/howtox.html#add-math-library-lm-portably
+m_dep = cc.find_library('m', required: false)
+rt_dep = cc.find_library('rt', required: false)
+xcb_dep = dependency('xcb', method: 'pkg-config')
+xcb_xkb_dep = dependency('xcb-xkb', method: 'pkg-config')
+xcb_xinerama_dep = dependency('xcb-xinerama', method: 'pkg-config')
+xcb_randr_dep = dependency('xcb-randr', method: 'pkg-config')
+xcb_image_dep = dependency('xcb-image', method: 'pkg-config')
+xcb_util_dep = dependency('xcb-util', method: 'pkg-config')
+xcb_util_xrm_dep = dependency('xcb-xrm', method: 'pkg-config')
+xkbcommon_dep = dependency('xkbcommon', method: 'pkg-config')
+xkbcommon_x11_dep = dependency('xkbcommon-x11', method: 'pkg-config')
+cairo_dep = dependency('cairo', version: '>=1.14.4', method: 'pkg-config')
+i3lock_srcs = [
+  'dpi.c',
+  'extras.c',
+  'i3lock.c',
+  'randr.c',
+  'unlock_indicator.c',
+  'xcb.c',
+]
+ev_dep = cc.find_library('ev')
+thread_dep = dependency('threads')
+i3lock_deps = [
+  thread_dep,
+  m_dep,
+  rt_dep,
+  ev_dep,
+  config_h,
+  cairo_dep,
+  xcb_dep,
+  xcb_xkb_dep,
+  xcb_xinerama_dep,
+  xcb_randr_dep,
+  xcb_image_dep,
+  xcb_util_dep,
+  xcb_util_xrm_dep,
+  xkbcommon_dep,
+  xkbcommon_x11_dep,
+]
+host_os = host_machine.system()
+if host_os != 'openbsd'
+  pam_dep = cc.find_library('pam', required: true)
+  i3lock_deps += [pam_dep]
+endif
+inc = include_directories('include')
+executable(
+  'i3lock-extended',
+  i3lock_srcs,
+  install: true,
+  include_directories: inc,
+  dependencies: i3lock_deps,
+)
+install_subdir(
+  'pam',
+  strip_directory: true,
+  install_dir: join_paths(get_option('sysconfdir'), 'pam.d'),
+)
diff --git a/meson/meson-dist-script b/meson/meson-dist-script
new file mode 100755
index 0000000..b112d2f
--- /dev/null
+++ b/meson/meson-dist-script
@@ -0,0 +1,11 @@
+#!/bin/sh
+set -eu
+cd "${MESON_DIST_ROOT}"
+# Delete everything we do not want to have in the release tarballs:
+rm -rf \
+   .clang-format \
+   .editorconfig \
+   travis
diff --git a/meson_options.txt b/meson_options.txt
new file mode 100644
index 0000000..5f1d584
--- /dev/null
+++ b/meson_options.txt
@@ -0,0 +1 @@
+# -*- mode: meson -*-
diff --git a/travis/Dockerfile b/travis/Dockerfile
index cc2dd7d..9dc8137 100644
--- a/travis/Dockerfile
+++ b/travis/Dockerfile
@@ -16,10 +16,10 @@ RUN echo 'APT::Acquire::Retries "5";' > /etc/apt/apt.conf.d/80retry
 # test suite dependencies (for running tests)
 RUN apt-get update && \
    DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
-    build-essential clang git autoconf automake libxcb-randr0-dev pkg-config libpam0g-dev \
+    build-essential clang git meson libxcb-randr0-dev pkg-config libpam0g-dev \
    libcairo2-dev libxcb1-dev libxcb-dpms0-dev libxcb-image0-dev libxcb-util0-dev \
    libxcb-xrm-dev libev-dev libxcb-xinerama0-dev libxcb-xkb-dev libxkbcommon-dev \
-    libxkbcommon-x11-dev clang-format-9 && \
+    libxkbcommon-x11-dev  && \
    rm -rf /var/lib/apt/lists/*
 WORKDIR /usr/src
diff --git a/unlock_indicator.c b/unlock_indicator.c
index 8f69972..6f6fbf7 100644
--- a/unlock_indicator.c
+++ b/unlock_indicator.c
@@ -1,6 +1,6 @@
 /*
 * This file is part of i3lock-extended
- * Copyright (C) 2020 Simeon Simeonov
+ * Copyright (C) 2020-2023 Simeon Simeonov
 * i3lock-extended is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
@@ -31,6 +31,7 @@
 #include <string.h>
 #include <math.h>
 #include <xcb/xcb.h>
+#include <xkbcommon/xkbcommon.h>
 #include <ev.h>
 #include <cairo.h>
 #include <cairo/cairo-xcb.h>
@@ -103,6 +104,9 @@ extern bool show_failed_attempts;
 /* Number of failed unlock attempts. */
 extern int failed_attempts;
+extern struct xkb_keymap *xkb_keymap;
+extern struct xkb_state *xkb_state;
 /*******************************************************************************
 * Variables defined in xcb.c.
 ******************************************************************************/
@@ -122,6 +126,44 @@ static xcb_visualtype_t *vistype;
 unlock_state_t unlock_state;
 auth_state_t auth_state;
+/* check_modifier_keys describes the currently active modifiers (Caps Lock, Alt,
+   Num Lock or Super) in the modifier_string variable. */
+static void check_modifier_keys(void) {
+    xkb_mod_index_t idx, num_mods;
+    const char *mod_name;
+    num_mods = xkb_keymap_num_mods(xkb_keymap);
+    for (idx = 0; idx < num_mods; idx++) {
+        if (!xkb_state_mod_index_is_active(xkb_state, idx, XKB_STATE_MODS_EFFECTIVE))
+            continue;
+        mod_name = xkb_keymap_mod_get_name(xkb_keymap, idx);
+        if (mod_name == NULL)
+            continue;
+        /* Replace certain xkb names with nicer, human-readable ones. */
+        if (strcmp(mod_name, XKB_MOD_NAME_CAPS) == 0) {
+            mod_name = "Caps Lock";
+        } else if (strcmp(mod_name, XKB_MOD_NAME_NUM) == 0) {
+            mod_name = "Num Lock";
+        } else {
+            /* Show only Caps Lock and Num Lock, other modifiers (e.g. Shift)
+             * leak state about the password. */
+            continue;
+        }
+        char *tmp;
+        if (modifier_string == NULL) {
+            if (asprintf(&tmp, "%s", mod_name) != -1)
+                modifier_string = tmp;
+        } else if (asprintf(&tmp, "%s, %s", modifier_string, mod_name) != -1) {
+            free(modifier_string);
+            modifier_string = tmp;
+        }
+    }
+}
 /*
 * Draws global image with fill color onto a pixmap with the given
 * resolution and returns it.
@@ -291,7 +333,7 @@ void draw_image(xcb_pixmap_t bg_pixmap, uint32_t *resolution) {
            cairo_close_path(ctx);
        }
-        if (auth_state == STATE_AUTH_WRONG && (modifier_string != NULL)) {
+        if (modifier_string != NULL) {
            cairo_text_extents_t extents;
            double x, y;
@@ -432,6 +474,13 @@ void free_bg_pixmap(void) {
 */
 void redraw_screen(void) {
    DEBUG("redraw_screen(unlock_state = %d, auth_state = %d)\n", unlock_state, auth_state);
+    if (modifier_string) {
+        free(modifier_string);
+        modifier_string = NULL;
+    }
+    check_modifier_keys();
    if (bg_pixmap == XCB_NONE) {
        DEBUG("allocating pixmap for %d x %d px\n", last_resolution[0], last_resolution[1]);
        bg_pixmap = create_bg_pixmap(conn, screen, last_resolution, color);