[CM] Snd 9.2

[Bill Schottstaedt]

Snd 9.2

many Forth/Ruby improvements thanks to Mike.

RIFF bugfix and minGW configure info thanks to Steve Beet.

snddiff.scm
virtual-filter-channel (examp.scm)
max-virtual-ptrees (greatly expanded virtual editor)

added optional snd chn args to apply-ladspa and with-tag to mix-channel
power spectral density as transform (green.scm)

clm: mus-increment on gens with a notion of frequency (phase increment); 
       to make room for this, asymmetric-fm ratio and sine-summation b moved to mus-offset.
     exp envs optimized

Thanks!: Mike Scholz, Plutek, Etienne Deleflie, Steve Beet, Kjetil Matheussen, unknown_error

Checked: gtk 2.11.2|3|4|5, cairo 1.4.8|10, Fedora 7, sbcl 1.0.6|7