public static Uri UnescapeRelativeUri (Uri baseUri, string relativeUriString)
{
var relativeUri = new Uri (DecodeUrlString (relativeUriString) , UriKind.Relative);
var aboluteUri = new Uri (baseUri, relativeUri);
var unescapedRelativeUri = new Uri (aboluteUri.GetComponents (UriComponents.Path | UriComponents.KeepDelimiter, UriFormat.Unescaped), UriKind.Relative);
return unescapedRelativeUri;
}