The first argument in any signal is the object that emits it, so we don't have
to add it again.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
This is used by the GUI and by kete and it's just an abstraction of the
handling anyway with little actual logic. Let's make this sharable.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>