** Now implement file upload progress events
** http://dev.w3.org/2006/webapi/progress/Progress.html
** Old list of events:
** 3.0: progress, uploadprogress, load, abort, error
** 3.1: loadstart, progress, load, abort, error (uploadprogress still there but deprecated)
** all those events are fired on the XHR.upload property and fire for the uploading
* TraceMonkey testing via config