Deletes all links for a menu.
$menu_name: The name of the menu whose links will be deleted.
function menu_delete_links($menu_name) {
$links = menu_load_links($menu_name);
foreach ($links as $link) {
// To speed up the deletion process, we reset some link properties that
// would trigger re-parenting logic in _menu_delete_item() and
// _menu_update_parental_status().
$link['has_children'] = FALSE;
$link['plid'] = 0;
_menu_delete_item($link);
}
}