This is in a separate commit just to make the changes to existing files easier to go through.
git-svn-id: https://svn.eduke32.com/eduke32@8215 1a8010ca-5511-0410-912e-c29ae57300e0
# Conflicts:
# source/audiolib/include/midi.h
# source/audiolib/src/_midi.h
# source/audiolib/src/al_midi.cpp
# source/audiolib/src/midi.cpp
# source/audiolib/src/music.cpp
# source/audiolib/src/oplmidi.cpp
# source/duke3d/src/midi.cpp
# Conflicts:
# source/audiolib/src/al_midi.cpp
# source/audiolib/src/midi.cpp
# source/audiolib/src/music.cpp