[metacity] build: add AX_IS_RELEASE

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 7ef592b96e30883ea5a7a2d132d467383d57cf0d
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sun Sep 20 01:12:30 2015 +0300

    build: add AX_IS_RELEASE

 configure.ac |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 8d9188e..350e5bf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -12,6 +12,12 @@ AC_INIT([metacity], [metacity_version],
 AC_CONFIG_SRCDIR(src/core/display.c)
 AC_CONFIG_HEADERS(config.h)
 
+dnl **************************************************************************
+dnl Set release policy
+dnl **************************************************************************
+
+AX_IS_RELEASE([git-directory])
+
 AM_INIT_AUTOMAKE([1.11.1 no-dist-gzip dist-xz])
 m4_ifdef([AM_SILENT_RULES],[AM_SILENT_RULES([yes])],)
 AM_MAINTAINER_MODE([enable])