More use of list_active(), setup ajax actions that are check to be ajax

modules/product/classes/controller/product/category.php

@@ -34,8 +34,7 @@ class Controller_Product_Category extends Controller_TemplateDefault {
 	 */
 	private function _get_categories() {
 		return ORM::factory('product_category')
-			->where('status','=',TRUE)
-			->find_all();
+			->list_active();
 	}
 }
 ?>