Added support for Tiberian Sun MIX filename hashes

Implements #3227. I added @zzattack and @OlafvdSpek to AUTHORS because I read their code/documentation. Licenses from XCC and CNCMaps are also compatible.

Tested it with the Tiberian Sun and Firestorm AUD soundtrack loaded from SCORES.MIX:

![Music Player](http://media.moddb.com/images/articles/1/128/127390/auto/JIwOE9J.png)