freeze break request for gnome-shell/caribou keyboard interaction

[Dan Winship <danw gnome org>]

Under certain circumstances (especially if gnome-shell crashes and is
restarted), it's possible for antler (the "fallback" on-screen keyboard
that is part of caribou) to end up running under gnome-shell.

This is easy to fix, it's just a matter of picking the right dbus flags
when grabbing the unique name.

shell patch:
https://bugzilla.gnome.org/show_bug.cgi?id=659865

caribou patch:
https://bugzilla.gnome.org/show_bug.cgi?id=659867

-- Dan