title: knockout-kendo widgets with knockout validation not working
body: <p>I need to implement knockout validation with knockout-kendo.</p>
  
  <p>I have this html:</p>
  
  <pre><code>&lt;textarea class="k-textbox" data-bind="value: description"&gt;&lt;/textarea&gt;
  &lt;input data-bind="kendoComboBox: { 
                    data: myOptions, 
                    value:myOptionId,
                    dataTextField: 'MyOptionName', 
                    dataValueField: 'MyOptionId'}"/&gt;
  &lt;input data-bind="kendoDatePicker: {value: dueDate}"/&gt;
  </code></pre>
  
  <p>Javascript:</p>
  
  <pre><code>...
  viewModel: {
      description: ko.observable('').extend({ required: true }),
      dueDate: ko.observable('').extend({ required: true }),
      myOptions: ko.observableArray([]),
      myOptionId: ko.observable('').extend({ required: true })
  }
  ...
      ko.applyBindingsWithValidation(self.viewModel, $ctx[0]);
  </code></pre>
  
  <p>The validation works fine for the description field, bound to the text area; but it doesn't work for the comboBox or the datePicker. </p>
  
  <p>I have checked the documentation, and also <a href="http://jsfiddle.net/rniemeyer/h9JKx/" rel="nofollow">this</a> jsFiddle, but I haven't been able to get it to work.</p>
  
  <p>Any help would be greatly appreciated.</p>