Compatible with Rails4.  Fixed various bugs encountered

Added in the Rails 4.0.0.beta gem.

I had an issue with the `vendor` directory not being pulled into the gemspec, so I put that change in.  This isn't rails4 specific.

I also had an issue with `Rails.logger` not being found.  Since I didn't test with a non-rails4 app, I'm not sure if this is rails4 specific.  I reverted to the `ActiveRecord::Base` logger and it works fine.