FEATURE: prepare handlers for categories

modules/Gallery/Handlers/Gallery.php

@@ -237,4 +237,14 @@ class Gallery implements AppHandler
         // delete directory used as photogallery
         $directory->delete();
     }
+
+    /**
+     * Does this module support categories?
+     *
+     * @return boolean
+     */
+    public static function supportCategories()
+    {
+        return true;
+    }
 }