GtkOptionMenu::remove_menu
remove_menu() removes the
GtkMenu currently associated with the
GtkOptionMenu.
In order to avoid an error message the next time that the user clicks
on the GtkOptionMenu after menu removal, it is
necessary to either replace it with a new
GtkMenu or to call
set_sensitive(false) from the
GtkOptionMenu. Either call will avert an error
message regards the menu not existing.
