Comment 5 for bug 1136377

I extended reader.dll to provide this info via the texture.tag mechanism in the returned XNA Texture2D.

I had planned to provide the full channel info, but unfortunately I have no means to read the channels when an ACE file contains a DXT1 texture. As such I am only providing a boolean to indicate if a multibit alpha channels exists or not which I can determine from the available data.

SVN 1463 contains the changes.