424fc5245a
Currently keybindings are blocked while the compositor holds a grab; if we want a keybinding to be available anyway, we use captured ClutterEvents to determine the KeyBindingAction the event would have triggered and run our own handlers (ugh). Instead, provide a hook to allow the compositor to filter out keybindings before processing them normally, regardless of whether the compositor holds a grab or not. https://bugzilla.gnome.org/show_bug.cgi?id=688202
