title: Returning true doesn't allow default action in Knockout "event" binding
body: <p>According to the <a href="http://knockoutjs.com/documentation/event-binding.html#note-3-allowing-the-default-action" rel="nofollow noreferrer">Knockout docs for the &quot;event&quot; binding</a>:</p>
  <blockquote>
  <p>By default, Knockout will prevent the event from taking any default action.</p>
  <p>....</p>
  <p>However, if you <em>do</em> want to let the default action proceed, just return true from your event handler function.</p>
  </blockquote>
  <p>This doesn't seem to be working for me.  Here's my view:</p>
  <pre><code>&lt;input data-bind=&quot;event: { 'keydown': function(d, e) { onInputKeydown(e); } }&quot; /&gt;
  </code></pre>
  <p>and the event handler in my ViewModel:</p>
  <pre><code>onInputKeydown = function(e) {
      console.log(e.which);
      return true;
  }
  </code></pre>
  <p>This handler is preventing any characters from being entered into the <code>&lt;input&gt;</code> element.  What am I doing wrong?</p>