[CM] midishare revisited

[Rick Taube]

Ive reimplemented midishare so that it uses rts and set-receiver! for 
"real time" work rather than using midishare alarms and callbacks that 
dont seem to work well anyway.

  the midishare docs are completely reorganized as well, the single 
dictionary entry is now
	http://commonmusic.sf.net/doc/dict/midishare-topic.html
I tested the examples in Openmcl only.

since the midishare stream now behaves more like portmidi and 
supercollider i will add an sbcl ffi for it at some point.