title: How to refresh an image in gwt?
body: <p>I have a form with an Image widget and a FileUpload widget.
  I can use file upolad to change images.</p>
  
  <p>I'd like to visualise a changed image right after a new image is submited to a servlet. But how can I force an Image widget to grab a new image from server ? (image's url doesn't change, content does) .</p>