[kdbus] Integrate acquiring and releasing names on kdbus with GLib core

Now it's possible to use GLib API for owning bus names, like:
g_bus_own_name() or g_bus_own_name_on_connection(). It is not yet
fully functional until I'll add 'Add Match' method on kdbus, so
g_bus_unown_name() still doesn't invoke proper handler, when 'name'
is lost - work in progress.