Update to 3.4.1

Added Conflicts: gnome-shell < 3.4.1 to make sure this can't be
installed with gnome-shell 3.4.0 because of an ABI change in
meta_display_add_keybinding().

https://mail.gnome.org/archives/gnome-announce-list/2012-April/msg00021.html

.gitignore

@@ -28,3 +28,4 @@ mutter-2.31.5.tar.bz2
 /mutter-3.3.90.tar.xz
 /mutter-3.3.92.tar.xz
 /mutter-3.4.0.tar.xz
+/mutter-3.4.1.tar.xz