[CM] snd 7.16

[Bill Schottstaedt]

Snd 7.16

Marten Stromberg provided a PDF version of snd.html, but I can't decide
  where it should go.

new dialog: first half (Motif version) of a preferences dialog (Options menu item).

added cycle speed style via click, mix|track-speed-style
      analyze-ladspa as synonym for analyse-ladspa
      save/insert/mix buttons in region browser
      save-region-dialog
      --enable-threads configure switch, and first use thereof (FIR filtering)
      snd-g|xprefs.c, preferences-dialog function

snd-error is now (throw 'snd-error ...)

init file handling has become more complex: ~/.snd is still loaded if present,
  as is /etc/snd.conf, but Snd also now looks for ~/.snd_guile|ruby, and
  /etc/snd_guile|ruby.conf, and the preferences dialog and
  Options:save options function write to ~/.snd_prefs_guile|ruby
  (so that the user's init file is not changed by the preference mechanism).
  This may seem unmotivated, but watch this space!

changed recorder-in|out-format -> recorder-in|out-data-format,
        recorder-out-type -> recorder-out-header-type
        save-macros now requires a filename (it won't write to ~/.snd unless you ask it to)


Checked: gtk 2.8.3|4|5|6, FreeBSD 5.4, gsl 1.7, Ruby 1.8.3

With much help from: Anders Vinjar, Kjetil Matheussen, Mike Scholz, Marten Stromberg