The "watch" function functionality in xsettings-client.c is designed
for setups like GDK where filters are per-window. If we are going
to pass all events to _clutter_xsettings_client_process_event()
anyways, we can just pass in NULL for watch.
This avoids a nasty infinite loop where an event would get processed
triggering removing a filter and adding a new filter, which would
immediately run and remove a filter and add another and so on
ad-infinitum.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2415
9249bd8411