title: Simple JSON issue with kendo-grid
body: <p>Was wondering if you could help me, I've been battling with trying to get my rest JSON data to display correctly in a kendo-grid for a few hours now, and have just worked out it's due to additional nodes on my JSON</p>
  
  <pre><code>$(function() {
      var grid = $("#grid").kendoGrid({
          dataSource: {
              data: {
                  "ttPortalCommunicationResult": [{
                      "UniqueID": 7,
                      "DocumentTitle": "Expense Contribution Scheme Guide",
                      "ActivationDate": "2012-05-22",
                      "DeactivationDate": "2020-05-12",
                      "CategoryDesc": "Operational news"
                  }],
              },
  
              pageSize: 10,
              schema: {
                  data: "ttPortalCommunicationResult"
              }
          }
      }).data("kendoGrid");
  });
  </code></pre>
  
  <p>I get an error <code>Cannot read property 'slice' of undefined</code>.</p>
  
  <p>My question is how can I use only the "ttPortalCommunicationResult" node on JSON data which contains the additional nodes? </p>
  
  <p>I would have assumed kendo would understand how to traverse to that node. An explanation why it can't would also be nice.</p>