[CM] Snd 15.4

[Bill Schottstaedt]

Snd 15.4

before-save-as-hook arg order changed, also new-sound, save-region, save-selection, save-sound-as

deprecated output-name-hook, info-popup-hook, peak-env-hook, start-hook

changed s7_new_type_x args

mus-audio* deprecated (these haven't worked at all for a long time)
mus_set_name (and mus-set-name) deprecated

in CLM, Juan Reyes added sbcl support for gnuplot in dlocsig.lisp

checked: sbcl 1.2.8, gtk 3.15.5|7|8|9

Thanks!: Mike Scholz, Juan Reyes, Anders Vinjar, Michel Dutat