Change model_cache::clear() API to clear everything. This prevents

old ORM relationships from hanging around, which was causing problems
when doing MPTT manipulations (resulting in incorrect permission
propagation-- very bad!)

modules/gallery/libraries/ORM_MPTT.php

@@ -285,6 +285,7 @@ class ORM_MPTT_Core extends ORM {
 
     // Lets reload to get the changes.
     $this->reload();
+    $target->reload();
     return $this;
   }