[CM] Snd 20.0

[bil at ccrma.Stanford.EDU]

Snd 20.0:

Snd: Mike improved several Forth scripts.

s7: added baffle? and goto?

checked: sbcl 1.5.9, 2.0.0, Ubuntu 19.10

Thanks!: Kjetil Matheussen, Tito Latini, Matti Koskinen, David O'Toole,
          Michael Edwards, Mike Scholz.