[CM] snd - channel number during installation

[Bill Schottstaedt]

I added the variable "recorder-in-chans" which is currently
just a number -- if 0 (the default), you get as many inputs
as the recorder can find; otherwise it sets the number
of displayed inputs (apparently some audio cards insist
that you read 12 channels no matter what).  It should be
set before you start the recorder the first time, and not
changed thereafter.  (I'll add various features like
a list of desired channels and so on once I've goofed
around with this a bit).