libvorbis library version 1.3.5.
The following changes have been made:
- The following commits have been applied:
  - https://github.com/xiph/vorbis/commit/a79ec216cd119069c68b8f3542c6a425a74ab993
  - https://github.com/xiph/vorbis/commit/c1c2831fc7306d5fbd7bc800324efd12b28d327f
- Obviously, unnecessary folders and files (doc, examples, m4, macos, macosx,
  symbian, test, vq) have been removed.
- For building, premake is used to generate Visual Studio project files.
  See ../build/premake/ for details.
