add model for access control list

The schema is compatible with the distributed schema of the Security component.

Model/Acl/ObjectIdentityQuery.php

@@ -0,0 +1,18 @@
+<?php
+
+/**
+ * This file is part of the PropelBundle package.
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ *
+ * @license    MIT License
+ */
+
+namespace Propel\PropelBundle\Model\Acl;
+
+use Propel\PropelBundle\Model\Acl\om\BaseObjectIdentityQuery;
+
+class ObjectIdentityQuery extends BaseObjectIdentityQuery
+{
+
+}