Rails 3 parser; bundler; opengl 0.8.0

And I didn't know much about how pull requests work, I accidentally merged three commits into one. Sorry about that.

Commit 1, 151930d: Adds a parser for Rails 3 log files. Rails 3 splits information across
two lines (the beginning and end of the request), so the parser has
little knowledge of request size at first.

Commit 2, 25f6603: Switch gemspec management and Gemfile management to Bundler. Bundler is better at gem management, and the old hoe-based Rakefile requires a rather archaic version of hoe (< 2.0.0). 

Commit 3, 6d99b14: The instructions say opengl gem 0.7.0.pre1, but apparently 0.8.0 works well. I could not compile 0.7.0 (on OS X 10.8), so I believe this is a better solution.