title: Set the selected option by value in the Kendo DropDownList
body: <p>I have a kendo ui dropdownlist with angularjs in my html:</p>
  
  <pre><code>&lt;select kendo-drop-down-list="dropdownlistCatalogs" k-options="optionsDropDownListCatalogs" data-role="dropdownlist" style="display: none;"&gt;
     &lt;option value="2" selected="selected"&gt;Test1&lt;/option&gt;
     &lt;option value="3"&gt;Test2&lt;/option&gt;
     &lt;option value="4"&gt;Test3&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>In the angularjs controller, everytime i click on an item in the dropdownlist, i call this function to remove the selected item from the dropdown control:</p>
  
  <pre><code>function removeItemFromDropDown(e) {
     var index = e.item.index();
     var selectedItem = $scope.dropdownlistCatalogs.dataItem(e.item.index());
     $scope.optionsDropDownListCatalogs.dataSource.remove(selectedItem);
  }
  </code></pre>
  
  <p>Now, i want set the selected option to non existing item to show an empty value.</p>
  
  <p>I have tried with:</p>
  
  <pre><code>$scope.dropdownlistCatalogs.value(-1);
  </code></pre>
  
  <p>but not working</p>
  
  <p>How can i set the dropdownlist by value()?</p>