* Improve the midisyn layer a little.
* Add a driver for the Yamaha OPL[23] FM synths.
The opl driver is not finished yet; it sounds pretty awful.
For some strange reason I cannot get any FM sound from my SB64 cards,
but a regular SB16 works fine.
the /dev/rmidiN devices, or with a sequencer interface via /dev/music.
So far the only supported MIDI device is the MPU401 port on SoundBlaster
(and only on SB on isapnp, since we do not have locators with multiple
values yet).
