add flags to permissions groups

Flags can be added to permissions group to store some metadata.

An interface `PermissionsGroupFlagProvider` allow to add some flag to the form which create/
edit permissions groups.

Resources/config/doctrine/PermissionsGroup.orm.yml

@@ -14,6 +14,10 @@ Chill\MainBundle\Entity\PermissionsGroup:
         name:
             type: string
             length: 255
+        flags:
+            type: json
+            options: 
+                default: '[]'
     manyToMany:
         roleScopes:
             targetEntity: Chill\MainBundle\Entity\RoleScope

Resources/config/services/form.yml

@@ -33,6 +33,7 @@ services:
             - "@doctrine.orm.entity_manager"
         tags:
             - { name: form.type, alias: select2_chill_language }
+            
     chill.main.form.type.center:
         class: Chill\MainBundle\Form\Type\CenterType
         arguments:
@@ -130,5 +131,9 @@ services:
         arguments:
             $chillLogger: '@monolog.logger.chill'
             $passwordEncoder: '@Symfony\Component\Security\Core\Encoder\UserPasswordEncoderInterface'
+        tags:
+            - { name: form.type }
+            
+    Chill\MainBundle\Form\PermissionsGroupType:
         tags:
             - { name: form.type }