[CM] snd 7.4 etc

[Bill Schottstaedt]

Snd 7.4.

new sndins/gfm/ws.rb from Michael Scholz

snd-gtkrc picture from Frank Barknecht

new Snd/Scheme functions:

   dither-channel (dithering as a virtual op)
   goertzel in dsp.scm (much faster version of find-sine)
   complexify in snd-gl.scm (a different kind of 3D fft display)
   rotate-channel, reverse-channels, scramble-channels, scramble-channel.
   mono->stereo, mono-files->stereo, stereo->mono
   channel-variance etc in dsp.scm, taken from Julius Smith "Mathematics of the DFT"

Snd/CLM additions:

   added -start and -end args to sndplay, tied to dac function in CLM, added wait arg to dac

   new generator: average, make-average, average? ("moving window average")

   envelope arg to make-rand and make-rand-interp to give any arbitrary random number distribution
     the run time cost is an array-interp and a rand (via the "transformation method")
     the default is '(-1 1 1 1) which is uniform distribution between -1.0 and 1.0.
     the function used to integrate/invert the distribution is inverse-integrate in dsp.scm
     dsp.scm also has a gaussian distribution example

   mus-linear renamed mus-interp-linear, mus-sinusoidal -> mus-interp-sinusoidal
     added mus-interp-all-pass|none|lagrange|hermite|bezier

   delay and its friends (comb etc) now have a 'type' arg to set the interpolation type
     also type arg to mus_make_table_lookup|wave_train (not sure the latter makes sense)
     delay-tick added to make it easier to match physical modelling diagrams

   added Connes and Hann-Poisson windows

   some names changed (in C) from "2" to "_to_" to conform to modern practice

   changed sum-of-sines to sine-bank

   new sum-of-sines generator parallels sum-of-cosines

removed forward|backward-graph|mix|mark -- see snd7.scm for Scheme versions.
add-to-menu now returns the new menu label widget

Checked: Motif 2.2.4, Gtk+-2.4.1, Sbcl 0.8.10 (Linux), ACL 7.0 (Linux 7.3, Sun, OSX).

With much help from: Rick Taube, Michael Scholz, Dave Phillips,
     Frank Barknecht, Kjetil S. Matheussen, Stanko Juzbasic, Juan Reyes,
     Fernando Lopez-Lezcano, Matt Wright, Pat Pagano (...the usual suspects...)