Checks if image file (fn) with photo_id (pid) has already
        been resized on flickr. If so, returns True

def _already_resized_on_flickr(self,fn,pid,_megapixels):
        """Checks if image file (fn) with photo_id (pid) has already
        been resized on flickr. If so, returns True"""
        logger.debug("%s - resize requested"%(fn))
        # Get width/height from flickr
        width_flickr,height_flickr=self._getphoto_originalsize(pid)
        # Now compute what image will be if we resize it
        new_width,new_height=pusher_utils.resize_compute_width_height(\
                fn,_megapixels)
        if width_flickr==new_width and height_flickr==new_height:
            return True
        # Also return true if image couldn't be resized
        elif not new_width:
            return True
        return False