Upgrade RSpec to 2.10.x and refactor specs as needed

The included patch updates the Ruby library to utilized RSpec 2.10.1. This required some refactoring of the actual specs as they were extending from ExampleGroup, which as far as I can tell is not supported in RSpec 2. There were also a few other changes I had to make to get the specs working, but I believe they maintain the original intent of all specs. There's likely additional clean up and trimming that can be done, but that should happen separately.