launcher-button: Emit "fav-toggled" signal on the main instance.
launcher-button: Emit "fav-toggled" signal on the main instance.

When a launcher button was removed from the favs list by toggling
the pin in the favs list, the "fav-toggled" signal was emitted on
the fav button instance.

Fixes: http://bugs.meego.com/show_bug.cgi?id=1215

meego-netbook-ux/meego-panel-applications,meego-netbook-ux/meego-panel-applications