A modified version of 8bitbubsy's playptmod, a C-based player for ProTracker MOD
files, which was modeled after all the behavior that could be gleaned from
disassembling the original Amiga tracker program. This version has been adapted
into a self-contained library with an anonymous state structure, and also
supports more module formats, including multi-channel formats, and the
Multitracker MTM format, which was similar enough to MOD to be played by a
MOD player.