Log Message:
Update rabbit to 0.9.1.

== Changes 0.9.1 from 0.9.0: 2010-10-25

Changed license: Ruby's -> GPLv2 or later

=== Improvements

  * Removed rabbit.bat from gem. [U.Nakamura]
  * Added documentation for Homebrew. [kdmsnr]
  * Changed license to GPLv2 or later from Ruby's.
    (It assumed that Kouhei Sutou can change contributed
    codes and so on. If contributes can't accept the rule,
    those codes and so on aren't included in Rabbit.)

=== Thanks

  * U.Nakamura
  * kdmsnr