Release Name: 0.2.1

Notes:
I have released Rook 0.2.1
http://www.kuwata-lab.com/kook/
This is a bugfix release for supporing Ruby 1.8.6.

Features of Rook:
* Liken software build process to cooking.
* Two-style approach support: YAML-style and Ruby-style.
* Natural notation for production rule and optional ingredients.
* 'tar.gz', 'tar.bz2', and '.zip' support
  (requires 'minitar', 'bz2', and 'rubyzip' libraries.)
* Able to invoke build command forcedly

See users' guide (doc/users-guide.html) for details.



Changes:
bugfixes:
- ruby 1.8.6 support