title: preUpdate and postUpdate events not triggered on Doctrine 2
body: <p>I have followed the instructions from this tutorial: <a href="http://symfony.com/doc/current/cookbook/doctrine/event_listeners_subscribers.html" rel="noreferrer">http://symfony.com/doc/current/cookbook/doctrine/event_listeners_subscribers.html</a>, and have created a simple listener, that listens for events dispatched by Doctrine on insert or update of an entity. The preInsert and the postInsert events work fine and are dispatched on the creation of a new entity. However, preUpdate and postUpdate are never called on the update of the entity no matter what. The same goes for onFlush. As a side note, I have a console generated controller that supports the basic CRUD operations, and have left it untouched. </p>
  
  <p>Below are some code snippets to demonstrate the way I am doing this. </p>
  
  <p>config.yml</p>
  
  <pre><code>annotation.listener:
      class: City\AnnotatorBundle\Listener\AnnotationListener
      tags:
          -  { name: doctrine.event_listener, event: postUpdate}
  </code></pre>
  
  <p>Listener implementation (I have omitted the other functions and left only the postUpdate for simplicity purposes)</p>
  
  <pre><code>class AnnotationListener
  {
  
      public function postUpdate(LifecycleEventArgs $args)
      {
          $entity=$args-&gt;getEntity();
  
          echo $entity-&gt;getId();
          die;
      }
  }
  </code></pre>
  
  <p>The entity id is never displayed, and the script continues its execution until it is complete, despite the <b>die</b> at the end of the function.</p>