title: invalid date when using knockout.js and moment.js
body: <p>I'm using Knockout in combination with moment.js and C#.
  In C# i pass in a ISO formatted date by using:
      var jsonString = JsonConvert.SerializeObject(dataObject}, new IsoDateTimeConverter());</p>
  
  <p>In my HTML file i'm doing the following to display my date in a formatted way:</p>
  
  <pre><code>&lt;script type="text/javascript"&gt;
  var viewModel = {};
  $.getJSON("http://www.test.com/jsonfile.txt", function(data) { 
  viewModel.model = ko.mapping.fromJS(data);
  ko.applyBindings(viewModel);
  });
  &lt;/script&gt;
  &lt;div&gt;Hello&lt;/div&gt;
  &lt;div&gt;Time: &lt;span data-bind="text: moment(model.Time).format('L')"&gt;&lt;/span&gt;&lt;/div&gt;
  </code></pre>
  
  <p>I always get Invalid date but when i use:</p>
  
  <pre><code>&lt;div&gt;Time: &lt;span data-bind="text: model.Time"&gt;&lt;/span&gt;&lt;/div&gt;
  </code></pre>
  
  <p>it just displays correctly Time: 2014-08-25T09:49:00</p>
  
  <p>Anyone an idea what i'm doing wrong?</p>