[CM] Snd 15.0

[Bill Schottstaedt]

Snd 15.0:

clm and snd: Juan Reyes provided his banded waveguide instrument,
  bandedwg.ins and bandedwg.cms, and a Tibetan bowl: bowl.ins 
  and bowl.cms.

s7: *s7* is an environment holding various curiousities.
    moved *gc-stats*, *safety*, and *maximum-stack-size* into *s7*
    added cutlet to remove a binding from an environment

checked: gtk 3.13.7|8|9, sbcl 1.2.3

Thanks!: Juan Reyes