[CM] snd command line

[bil at ccrma.Stanford.EDU]

The workaround for the pipewire problem in Snd
(or repl.scm in s7) is to

(define stderr-buffered #t)

in your Snd init file, or if you're not using one,
put that line at the top of repl.scm.

I run the no-gui Snd in Ubuntu 22.04, and I think
it is using pipewire (/usr/bin/pipewire is reported
in ps aux), but I don't have to use that workaround.
You can get the "dumb repl" by moving repl.scm
to some other filename.