Mutter shares most (currently all) its keybindings with Metacity, and uses
the same /apps/metacity GConf keys. For 2.28, the schemas stay in Metacity;
the eventual plan is to have a gnome-wm-data package.
This patch allows a window manager to put a _GNOME_WM_KEYBINDINGS property
on its _NET_SUPPORTING_WM_CHECK window to provide a comma separated list of
window manager names to use for keybinding lookup instead of _NET_WM_NAME.
http://bugzilla.gnome.org/show_bug.cgi?id=594066
