add a ScopePickerType and a UserPickerType

Those type allow easily to

- pick a Scope/circle in form
- pick a user in form

Entity/RoleScope.php

@@ -45,8 +45,15 @@ class RoleScope
      */
     private $scope;
     
+    /**
+     *
+     * @var \Doctrine\Common\Collections\Collection
+     */
+    private $permissionsGroups;
+    
     public function __construct() {
         $this->new = true;
+        $this->permissionsGroups = new \Doctrine\Common\Collections\ArrayCollection();
     }
     
     public function getId()