[CM] Receiving from portmidi

[Rick Taube]

nando, its been a while but i believe that the functions im using:

	recv
	recv-set!
	recv-stop
	recv?

are supposed to be the receiving api for CM. these generic functions  
are defined in the CM package they get specialized for any port that  
supports receiving. for example if you look in the Osc system you  
will find methods on the same functions.

this might be something that didnt get updated in the doc.