title: Edit arrays using angular-xeditable
body: <p>I pull some objects from my api using ngResource an then I show them in a table. Thats ok.. the problem become when I try to make 'tags' attribute editable using angular-xeditable but are treated as string and there isn't something like "ngList" on angular-xeditable.
  The only solution I can think of is serialize that "tags" attribute to "tagsString" on my service and unserialize it once $save() was called.. there is a more elegant solution?</p>
  
  <p>Object:</p>
  
  <pre><code>{
      "id": "yP8",
      "uploadDate": "2012-10-03T12:52:59-0300",
      "statusChangeDate": "2012-10-03T12:52:59-0300",
      "status": 0,
      "type": 1,
      "mimeType": "JPEG",
      "title": "title-36868",
      "tags": [
          'some-tag',
          'fancy-tag'
      ],
      "language": "en",
      "interactions": {
          "likes": 12371,
          "dislikes": 15,
          "comments": 81
      },
      "published": true
  }
  </code></pre>
  
  <p>Controller:</p>
  
  <pre><code>app.controller( 'ContentsCtrl', function CommentsCtrl( $scope, Contents ) {
      $scope.contents = Contents.query();
  });
  </code></pre>
  
  <p>Template:</p>
  
  <pre><code>&lt;tr ng:repeat="content in contents.content"&gt;
      &lt;td&gt;{{content.id}}&lt;/td&gt;
      &lt;td ng:click="content.images.showFull=!content.images.showFull"&gt;
          &lt;img src="{{content.images.thumbnail.url}}" ng:show="!content.images.showFull"&gt;
          &lt;img src="{{content.images.medium.url}}" ng:show="content.images.showFull"&gt;
      &lt;/td&gt;
      &lt;td&gt;{{content.status}}&lt;/td&gt;
      &lt;td&gt;
          &lt;span editable-text="content.title" e-required&gt;{{content.title}}&lt;/span&gt;
      &lt;/td&gt;
      &lt;td&gt;
          &lt;span editable-text="content.tags"&gt;{{content.tags}}&lt;/span&gt;
      &lt;/td&gt;
      &lt;td&gt;{{content.language}}&lt;/td&gt;
  &lt;/tr&gt;
  </code></pre>
  
  <p>EDIT:</p>
  
  <p>Demo (by Sebastian Gärtner):
  <a href="http://plnkr.co/edit/ttPNgHXUZKmaJZ9IuB2N?p=preview">http://plnkr.co/edit/ttPNgHXUZKmaJZ9IuB2N?p=preview</a></p>