title: renderView fails when using Symfony2 with SwiftMail
body: <p>I want to use SwiftMailer in Symfony2.
  To start with, I created a new controller and copied the sample from <a href="http://symfony.com/doc/current/cookbook/email/email.html" rel="nofollow">http://symfony.com/doc/current/cookbook/email/email.html</a>.
  When I try to execute <code>renderView</code> I get the following error-message: <code>Fatal error: Call to a member function get() on a non-object in  var/www/project/Symfony/vendor/symfony/src/Symfony/Bundle/FrameworkBundle/Controller/Controller.php on line 84</code>.</p>
  
  <p>I tried various things, but they always will end up in an error in the controller.</p>
  
  <p>Not only <code>renderView</code> but also <code>$this-&gt;get('mailer')-&gt;send($message);</code> is throwing an error.</p>