title: How could process windows auth handshake (401) for ajax call in extjs 3.4?
body: <p>I have a store with linked proxy (use GET method) - it works fine in IE, but not working with Chrome and other modern browser's. IE can work with 401 with
  <code>WWW-Authenticate: Negotiate TOKEN</code> header and send another one request with 
  <code>Authorization: Negotiate TOKEN</code>, but Chrome stops on 401.
  Is any best-practice to work with it? Or i should try to check and retry request manually?</p>