-  Added stuff into configure.in to detect FLAC libraries and headers
   (should autodetect correctly, but you can also force it off with
   --without-flac) as well as setup conditional building.
- FLAC is not required to build ogg123 (unlike curl).
- Reads both FLAC and Ogg FLAC
- Refactored vorbis comment pretty printing into separate file since it
  is shared by both FLAC and Vorbis readers (and future Speex reader will
  need it too)
- Fixed bug caused by assuming Vorbis comments were null terminated.

svn path=/trunk/vorbis-tools/; revision=4222