Log Message:
Update ruby-rdtool to 0.6.33.

= CHANGES
:0.6.33
  * Typo fixed
  * Remove makerdtool.rb, merge Rake task.
:0.6.32
  * Fix for Ruby 1.9.1. Thanks to Shin-ya Murakami
  * Update Rakefile to create gem and .tar.gz, no longer needed jeweler.
  * Add RD::Version into rd/version.rb