Freeze break request for gtk, totem

[Matthias Clasen <matthias clasen gmail com>]

The new GtkMenuButton widget has a gtk_menu_button_set_menu function
that we've renamed to gtk_menu_button_set_popup shortly after
introducing the widget, and I would like to drop the old name before
it makes it out into a stable release. The only known user of this
function is totem, for which I've just filed a patch in
https://bugzilla.gnome.org/show_bug.cgi?id=684695