[gtkmm-documentation] Auto-generate the ChangeLog from the git log for 'make dist'.

[José Alburquerque <jaalburqu src gnome org>]

commit 4fd65bbb99525fac71ebc92e8f65ecf3ecbe2728
Author: José Alburquerque <jaalburquerque gmail com>
Date:   Tue Jul 2 17:38:06 2013 -0400

    Auto-generate the ChangeLog from the git log for 'make dist'.
    
        * autogen.sh: Call mm-common-prepare with the --copy and --force flags
        so that the additional dist-changelog.am file from mm-common (among
        others) can be copied to the build/ directory so that it is possible
        to include that file so that auto-generation of the ChangeLog from the
        git commit messages is possible on 'make dist'.
        * Makefile.am: Include the mentioned .am file so that the ChangeLog is
        automatically generated from the git commit messages on 'make dist'.
        * configure.ac: Check for 'sed' which is used for the ChangeLog
        generation from the git commit messages on 'make dist'.

 Makefile.am  |    3 +++
 autogen.sh   |    9 +++++++--
 configure.ac |    1 +
 3 files changed, 11 insertions(+), 2 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index 5b31b53..b383759 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -12,3 +12,6 @@ SUBDIRS = examples $(doc_subdirs)
 
 dist_noinst_DATA = COPYING.examples
 dist_noinst_SCRIPTS = autogen.sh
+
+# Auto-generate the ChangeLog file from the git log on make dist
+include $(top_srcdir)/build/dist-changelog.am
diff --git a/autogen.sh b/autogen.sh
index 0d901e7..5f906ec 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -1,8 +1,13 @@
 #! /bin/sh -e
 test -n "$srcdir" || srcdir=`dirname "$0"`
 test -n "$srcdir" || srcdir=.
- # gtkmm-documentation depends on the mm-common module. Stop if it's not installed.
-mm-common-prepare --version
+
+# gtkmm-documentation depends on the mm-common module. Stop if it's not
+# installed.
+# Also copy files from mm-common to the build/ directory so that things like
+# auto-generating the ChangeLog from the git commit messages on 'make dist' is
+# possible.
+mm-common-prepare --copy --force "$srcdir"
 
 (
   cd "$srcdir" &&
diff --git a/configure.ac b/configure.ac
index c2e2121..474816e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,6 +17,7 @@ AC_ARG_VAR([ACLOCAL_FLAGS], [aclocal flags, e.g. -I <macro dir>])
 
 AC_PROG_CXX
 AC_PATH_PROG([PERL], [perl], [perl])
+AC_PROG_SED
 
 PKG_CHECK_MODULES([GIOMM], [giomm-2.4 >= 2.32.0])
 PKG_CHECK_MODULES([GTKMM], [gtkmm-3.0 >= 3.4.0])