title: JMSSerializerBundle with FOSRESTbundle serializes 'GET' with 'entities' tag
body: <p>I'm using FOSRestBundle and JMSSerializationBundle. When I get a Collection I get something like this:</p>
  
  <pre><code>{ "entities": [
      {
          "id": 1,
          "mainDiagnosticName": "diagnostic",
          "mainDiagnosticCode": "code",
          "startDate": "2011-01-04T21:30:40+0000",
          "endDate": null,
          "patient": null
       }]
   }
  </code></pre>
  
  <p>I don't want the entities stuff. I just want: </p>
  
  <pre><code> [
      {
          "id": 1,
          "mainDiagnosticName": "diagnostic",
          "mainDiagnosticCode": "code",
          "startDate": "2011-01-04T21:30:40+0000",
          "endDate": null,
          "patient": null
       }]
  </code></pre>
  
  <p>How this can be done?</p>
  
  <p>Many Thanks.</p>