Tue Feb  3 15:09:55 1998  Tim Janik  <timj@gimp.org>

        * gtk/testgtk.c: don't add the same menu to different menuitems/
          optionmenus.

        * gtk/gtkmenuitem.h:
        * gtk/gtkmenuitem.c: new function gtk_menu_item_remove_submenu ro
          be consistent with optionmenu. use gtk_menu_attach_to_widget/
          gtk_menu_detach for setting/removing the submenu.
          invoke gtk_widget_destroy(submenu) in destructor to be consistent
          with other destructors.

        * gtk/gtkoptionmenu.h:
        * gtk/gtkoptionmenu.c: attach/detach to menu widget via
          gtk_menu_attach_to_widget/gtk_menu_detach.
          invoke gtk_widget_destroy(menu) in destructor to be consistent
          with other destructors.