title: Symfony2 FOSUserBundle and groups error
body: <p>i am getting an error, when applying </p>
  
  <pre><code>php app/console doctrine:schema:update --force
  </code></pre>
  
  <p>i get a stack of errors, starting with</p>
  
  <pre><code>PHP Fatal error:  Declaration of Tracker\MembersBundle\Entity\User::addGroup() must be 
  
  compatible with that of FOS\UserBundle\Model\GroupableInterface::addGroup() in C:\Program Files (x86)\Zend\Apache2\htdocs\mysite\src\Tracker\MembersBundle\Entity\User.php on line 14
  PHP Stack trace:
  PHP   1. {main}() C:\Program Files (x86)\Zend\Apache2\htdocs\mysite\app\console:0
  PHP   2. Symfony\Component\Console\Application-&gt;run() C:\Program Files (x86)\Zend\Apache2\htdocs\mysite\app\console:22
  PHP   3. Symfony\Bundle\FrameworkBundle\Console\Application-&gt;doRun() C:\Program Files (x86)\Zend\Apache2\htdocs\mysite\vendor\symfony\src\Symfony\Component\Console\Application.php:118
  PHP   4. Symfony\Component\Console\Application-&gt;doRun() C:\Program Files (x86)\Zend\Apache2\htdocs\mysite\vendor\symfony\src\Symfony\Bundle\FrameworkBundle\Console\Application.php:75
  </code></pre>
  
  <p>i figured out <code>User::addGroup()</code> and the <code>groups</code> implementation of <code>FOSUserBundle</code> ...but i do not know how to ultimately solve it...here are my two entities</p>
  
  <p><a href="http://pastebin.com/vbgypx3K" rel="nofollow">User</a>
  <a href="http://pastebin.com/wejKfGVU" rel="nofollow">Group</a></p>
  
  <p>Update:
  if i simply remove addGroup() from the User Entity, and go to the path
  <a href="http://mysite.com/app_dev.php/group/new" rel="nofollow">http://mysite.com/app_dev.php/group/new</a>
  i get a fatal error</p>
  
  <pre><code> Fatal error: Declaration of FOS\UserBundle\Form\Type\GroupFormType::getDefaultOptions() must be compatible with that of Symfony\Component\Form\FormTypeInterface::getDefaultOptions() in C:\Program Files (x86)\Zend\Apache2\htdocs\mysite\vendor\bundles\FOS\UserBundle\Form\Type\GroupFormType.php on line 18
  </code></pre>