Alters HashMap#source_element to deal with a string source in 1.9.3.
Updates Gemfile for ruby 1.9.3
Use ruby-debug if ruby version is 1.8
Forgot to delete this require before committing.
Merge pull request #1 from natesalisbury/ruby-1.9.3

Updates Gemfile for ruby 1.9.3
Merge pull request #3 from ewollesen/ruby-1.9.3

Ruby 1.9.3