[gnome-shell] Bump version to 3.21.91

[Florian Müllner <fmuellner src gnome org>]

commit 622e73c34cb8c0a483a4a39abf362b90085ab7ea
Author: Florian Müllner <fmuellner gnome org>
Date:   Tue Aug 30 00:26:31 2016 +0200

    Bump version to 3.21.91
    
    Update NEWS.

 NEWS         |    7 +++++++
 configure.ac |    4 ++--
 2 files changed, 9 insertions(+), 2 deletions(-)
---
diff --git a/NEWS b/NEWS
index d50df1c..0825441 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,10 @@
+3.21.91
+=======
+Translations:
+  Mario Blättermann [de], Jiri Grönroos [fi], Dušan Kazik [sk],
+  Andika Triwidada [id], Daniel Mustieles [es], Fabio Tomat [fur],
+  Enrico Nicoletto [pt_BR], Matej Urbančič [sl], Мирослав Николић [sr, sr@latin]
+
 3.21.90.1
 =========
 Contributors:
diff --git a/configure.ac b/configure.ac
index f655680..33fe2f4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,5 +1,5 @@
 AC_PREREQ(2.63)
-AC_INIT([gnome-shell],[3.21.90.1],[https://bugzilla.gnome.org/enter_bug.cgi?product=gnome-shell],[gnome-shell])
+AC_INIT([gnome-shell],[3.21.91],[https://bugzilla.gnome.org/enter_bug.cgi?product=gnome-shell],[gnome-shell])
 AX_IS_RELEASE([git-directory])
 
 AC_CONFIG_HEADERS([config.h])
@@ -78,7 +78,7 @@ AC_MSG_RESULT($enable_systemd)
 CLUTTER_MIN_VERSION=1.21.5
 GOBJECT_INTROSPECTION_MIN_VERSION=1.49.1
 GJS_MIN_VERSION=1.39.0
-MUTTER_MIN_VERSION=3.21.90
+MUTTER_MIN_VERSION=3.21.91
 GTK_MIN_VERSION=3.15.0
 GIO_MIN_VERSION=2.45.3
 LIBECAL_MIN_VERSION=3.5.3