Change music folders to new ones

[Jezulkim]

This would allow "more" folders for ttd music, for example if you already have filled the three folders and don't want to cut and copy the files. With this feature you'd only have to change a line in the ttdpatch.cfg like "new music folders: awe,gm,fm" to "new music folders: awe2,gm,fm". This would make ttdp search the music files from awe2, gm and fm folders instead of awe, gm and fm.