#37 OPL emu ala ZDoom

[Anonymous]

I've always had a problem with Doom ports using the OS' MIDI synth for
music, as the original used the OPL FM synth found in SoundBlaster and
Adlib soundcards. ZDoom has an OPL emulation option for music, so I
think it would be a good idea to include it here too for us Linux and Mac
users.