title: TYPO3 returns "Array" to Fluid as String
body: <p>I try to pass an array within my Viewhelper to the Fluidtemplate.
  It always shows the string "Array". If I try to use it as parameter in the <code>f:for each</code> viewhelper, I get an exception because it is a string and not an array.
  I used Typo3 6.2 before, now I have Typo3 7 and it stopped working.</p>
  
  <pre><code>public function render($uids) { // $uids='901,902,903'
      $uidArray = explode(',', $uids);
  
      $objectManager = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance('TYPO3\\CMS\\Extbase\\Object\\ObjectManager');
      $repository = $objectManager-&gt;get('XXX\\X\\Domain\\Repository\\FooRepository');
      $query = $repository-&gt;createQuery();
      $query-&gt;getQuerySettings()-&gt;setRespectStoragePage(FALSE);
      $query-&gt;matching(
          $query-&gt;in('uid', $uidArray)
      );
      return $query-&gt;execute()-&gt;toArray();
  }
  </code></pre>
  
  <p>This is my Fluid template:</p>
  
  <pre><code>{namespace vh=My/Namespace/ViewHelpers}
  &lt;f:for each="{vh:GetArray(uids: '901,902,903')}"&gt;...&lt;/f:for&gt;
  </code></pre>