mpu401 module update

Hi,

Some good news with the mpu401 module:   Its starting to shape up.   I was able to fix the midi operations of the Emuxki driver, which uses the published header file "v1", and do some testing.   With the midi-in enabled and interrupts enabled I was able to test all midi functions and they are working pretty good so far.  Theres still some things with the midi-in buffers that I want to look at and figure if there is a more efficient method.   

I went another step further and replaced all midi components with the OpenBeos midi_server, libraries, OpenBeos emuxki SBLive driver and try it out.   Midi-out data worked without a hitch.   Midi-in data for key-on worked too.   One problem though, is the key-off messages were not handled.   My keyboard I was using ( an old Casio), does not seem to send complete key-off.  Key-on sends a 3 byte message (1st byte is 0x90), key-off sends only 2 bytes ( skips the first byte 0x80).   The Be server accepted the messages, but I don't know if my keyboard is odd in that fashion. 

My current code for submission: 
http://mywebpages.comcast.net/gsc70/mpu401.zip 

Greg Crain
Gsc70_at_comcast.net