Fix missing App::uses() added

Fixes #2374

Signed-off-by: mark_story <mark@mark-story.com>

lib/Cake/Model/Aco.php

@@ -17,6 +17,7 @@
  */
 
 App::uses('AppModel', 'Model');
+App::uses('AclNode', 'Model');
 
 /**
  * Access Control Object

lib/Cake/Model/Aro.php

@@ -17,6 +17,7 @@
  */
 
 App::uses('AppModel', 'Model');
+App::uses('AclNode', 'Model');
 
 /**
  * Access Request Object