GumpImageBrowser.cs - SGI Command 1.2

Removed reliance on Ultima.Gumps for this version. This may improve compatibility.

If you don't have VnC, all you need is the file EnumerableExt.cs, which I will attach to the discussion thread.

I had originally passed the X and Y coordinates of the Gump image, but I forgot I needed to subtract the default location so that the "starting point" was at 0, 0.