[metacity/gnome-3-18] bump version to 3.18.4, update NEWS

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 660c569398797d3dfc7b8a777bc5a6d60f90c497
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sun Apr 24 16:45:58 2016 +0300

    bump version to 3.18.4, update NEWS

 NEWS         |    6 ++++++
 configure.ac |    2 +-
 2 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/NEWS b/NEWS
index 53352c7..0c878d5 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,9 @@
+Version 3.18.4
+- Try to use root window background instead of grey color.
+- Fix performance regression.
+- Updated translations:
+  Anders Jonsson (sv).
+
 Version 3.18.3
 - Add Icon=preferences-system-windows in metacity.destkop. (Alberts Muktupāvels)
 - Scale window decorations on HiDPI displays, based on mutter. (Alberts
diff --git a/configure.ac b/configure.ac
index cad7029..5f846fd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4,7 +4,7 @@ dnl **************************************************************************
 
 m4_define([m_major_version], [3])
 m4_define([m_minor_version], [18])
-m4_define([m_micro_version], [3])
+m4_define([m_micro_version], [4])
 m4_define([m_version], [m_major_version.m_minor_version.m_micro_version])
 
 dnl **************************************************************************