Log message:
Update to 12.17.4; add dependency on mad.

Selection of changes:
* Various bugfixes to Ogg Vorbis handler as well as updating
  to use version 1.0 of library.  Also, modified the files
  that are output by Ogg Vorbis handler to use VBR format.
* Minor cleanups to sox.c to free and close all files instead
  of relying on C library to do it on exit.
* Fixed some integer overflow problems in compand effect.
* libst prototype cleanups and private data structure
  cleanups.
* Added new handler for Psion Record.app files.
* Play/Record scripts now look at an AUDIODEV
  enviornment variable to see what audio device to
  play to.  Also scripts to work on Sun Rays.
* Added support for reading and writing MP3 files if
  external MP3 libraries are avaliable.
* Fix multile channel bug in avg effect.
* Allow AIFF files with an invalid length of 0 to be
  processed.

Log message:
Enable vorbis support. Bump to 12.17.3nb1.

Log message:
buildlink1 -> buildlink2

Log message:
Update to sox 12.17.3.  Numerous bugs fixed, and most of the NetBSD patches
integrated.