Finally the trash, which was the last item that
needed to be implemented as an action, is an
action, a KatzeArrayAction to be exact.
This simplifies more code and also makes Window
and RecentlyVisited generically implementable.
Incidentally this change also fixes a bug where
the browser tried to add a new tab when the last
one was closed, even while destroying itself.
Furthermore sokoke_image_menu_item_ellipsized
and sokoke_widget_popup were promoted to Katze.
We're still keeping the old functions for now.