[packagekit] gnome-packagekit hiding buttons it doesn't support

[Ken VanDine]

I just pushed a change (72cc890216e04b5dda7813b1ce23344f9d3f65c8) to
hide buttons for actions that aren't supported by the backend.  I
think generally it is a good idea, but the placement doesn't change.
So we could end up with holes..  I don't have the skills to really fix
that... looking for volunteers to make that collapse better :)

Thanks,
-- 
Ken VanDine
http://ken.vandine.org