TinyXML fixes: linebreaks, license junk

TinyXML currently uses Windows linebreaks on Windows and Mac linebreaks on Mac. This creates minor disasters if two people collaborate on a Polycode project via version control.

Pick one, standardize on it. I picked Windows, for no particular reason, but you can change this via the define macro I added.

Also, the tinyxml license requires a notice if tinyxml has been changed from the default distribution. There is not one currently I see. I added one.