Fixed DownLoadImage routine in Core/Util/Utils.cs

see http://forum.team-mediaportal.com/posts/1098788 for complete description. I suggest also trying DownLoadImage as a function and not as a void procedure in order to evaluate the result returned. Last modification using guidelines proposed by Team MediaPortal. Also marqued older entry point ...void DownLoadImage(string strURL, string strFile, System.Drawing.Imaging.ImageFormat imageFormat) as obsolete (not used at this time)