add: wwmenu->on_destroy = cleanupWindowsMenu;
context: addWindowsMenu(WScreen *scr, WMenu *menu, char *title){    WMenu *wwmenu;    WWindow *wwin;    WMenuEntry *entry;    if (scr->flags.added_windows_menu) {	wwarning(_("There are more than one WINDOWS_MENU commands in the applications menu. Only one is allowed."));	return NULL;    } else {	scr->flags.added_windows_menu = 1;	wwmenu = wMenuCreate(scr, _("Window List"), False);	scr->switch_menu = wwmenu;	wwin = scr->focused_window;	while (wwin) {	    UpdateSwitchMenu(scr, wwin, ACTION_ADD);	    wwin = wwin->prev;	}	entry = wMenuAddCallback(menu, title, NULL, NULL);	wMenuEntrySetCascade(menu, entry, wwmenu);    }    return entry;}