[CM] snd 5.10

[Bill Schottstaedt]

Changes in Snd 5.10:

Snd can handle files of any size with aplomb.

--with-run is now the default (Guile 1.5 or later).
The optimizer is going well enough that I started moving some
functions into Scheme (snd5.scm) that existed simply to speed up
stuff: vct-do!, vcts-map!, vcts-do!.  The latter were trying to deal
with locsig-like applications, but CLM-2's locsig (which came later)
returns a frame, not a list, leaving the vcts-* without any purpose in
life.  Also added vct-map with arguments more like Scheme's.

added optimization-hook (to find out why the optimizer gave up)

Added singer.scm, piano.scm, maraca.scm, fade.scm, all
translated from CLM. singer.scm runs 20 times faster optimized!

Thanks to Anders Vinjar, Stefan Schwandter, David Baker, Ashley Gadd,
Dave Phillips, Michael Klingbeil, Brett Battey, and Fernando Lopez-Lezcano
for bug reports and bugfixes.