void OnInstallerDownloaderProgress (HttpDownloader obj)
{
string downloaded = Math.Round (obj.State.TotalBytesRead / 1024d / 1024d, 1).ToString ("F1");
string total = Math.Round (obj.State.TotalBytesExpected / 1024d / 1024d, 1).ToString ();
string rate = Math.Round (obj.State.TransferRate / 1024d, 1).ToString ("F1");
job.Progress = obj.State.PercentComplete;
job.Status = String.Format ("{0} MB / {1} MB ({2} KB/s)", downloaded, total, rate);
}