title: ko.mapping is undefined
body: <p>im following this example <a href="http://jsfiddle.net/rniemeyer/badZb/" rel="noreferrer">http://jsfiddle.net/rniemeyer/badZb/</a> . I just copy and paste the exact code into a sample application and it gave me this error : "ko.mapping is undefined" . Anyone know whats happening? My ko.observable and dependentObservable are working great, is just that ko.mapping is not working.</p>
  
  <p>FYI : The knockout.js version is 2.0 and Jquery 1.7.1</p>