title: Disable symfony 2 csrf token protection on ajax submit
body: <p>i'm building a mobile app talking to my symfony2 app via webservices
  I can't find a way to disable csrf protection on a specific controller/action</p>
  
  <p>i want to post registration data to this action and use sf2 form validation. I do not call the form in my mobile app</p>
  
  <p>Can't change container parameters in action, throw an exception because it is a frozen parameter...</p>
  
  <p>I do not want to disable form protection for whole my application</p>
  
  <p>any clue ?</p>
  
  <p>thanks !</p>
  
  <p><strong>update: with symfony 2.1.x</strong></p>
  
  <pre><code>/**
   * {@inheritdoc}
   */
  public function setDefaultOptions(OptionsResolverInterface $resolver)
  {
      $resolver-&gt;setDefaults(array(
          'csrf_protection'   =&gt; false,
      ));
  }
  </code></pre>