Remove Menu::compact() in favor of putting an if-then clause in

menu.html.php.  This serves two purposes:

1) It's more efficient since we're doing less passes over the Menu tree
2) We're allowing themers to decide whether or not to show empty menus

modules/gallery/libraries/Admin_View.php

@@ -47,7 +47,7 @@ class Admin_View_Core extends Gallery_View {
   public function admin_menu() {
     $menu = Menu::factory("root");
     module::event("admin_menu", $menu, $this);
-    return $menu->compact()->render();
+    return $menu->render();
   }
 
   /**