/// <summary>
/// This method returns a fully qualified absolute server Url which includes
/// the protocol, server, port in addition to the server relative Url.
/// 
/// Works like Control.ResolveUrl including support for ~ syntax
/// but returns an absolute URL.
/// </summary>
/// <param name="ServerUrl">Any Url, either App relative (~/default.aspx) 
/// or fully qualified</param>
/// <param name="forceHttps">if true forces the url to use https</param>