title: Checkbox binding in knockout not working on trigger event
body: <p>The checkbox data-binding value is not changing when i try to trigger the click event of checkbox.</p>
  
  <p>I have created a jsfiddle, when i click the button i expect the value bind to change but not. </p>
  
  <p><a href="http://jsfiddle.net/2T9QZ/13/" rel="noreferrer">http://jsfiddle.net/2T9QZ/13/</a></p>
  
  <p>Any help?</p>