An activity may have multiple reasons

The relationship between Activity and Reasons is now many-to-many.

Some improvement in show activity layout.

refs #4 #7

Form/ActivityType.php

@@ -85,7 +85,10 @@ class ActivityType extends AbstractType
             ))
             ->add('user')
             ->add('scope')
-            ->add('reason', 'translatable_activity_reason')
+            ->add('reasons', 'translatable_activity_reason', array(
+                'multiple' => true,
+                'required' => false
+            ))
             ->add('type', 'translatable_activity_type')
             //->add('person')
         ;