title: How to get pure XMLHTTPRequest object in jQuery 1.5?
body: <p>My code works fine in jquery 1.4 and i try upgrade it to 1.5.
  But this part of code stop working - its standard beforeSend handler</p>
  
  <pre><code>beforeSend: function (xhr, options) {
  //
  __forced_abort = false;
  
  //
  xhr.upload.addEventListener('progress', on_progress, false);
  xhr.upload.addEventListener('load', on_loaded, false);
  xhr.addEventListener('abort', on_abort, false);
  ....
  </code></pre>
  
  <p>I know that in 1.5 havent really xhr - just jqXHR highlevel abstraction and seems to be jqXHR not have upload attributes. </p>
  
  <p>Question: how get pure (old) xhr object in jQuery 1.5?</p>