WIP: Rails 4.0.x upgrade

Here is a WIP release of my Rails 4.0.x upgrade of railsgoat.

Here is the loose-ends that I know about:
  * Fix/Remove find/first warnings. Expect one line change in app/controllers/users_controller.rb file.
  * Remove **protected_attributes** and migrate to **strong_parameters**.
  * Known Misc Tasks:
    * Something related to Devise gem.
    * Upgrade rspec 2.99 to 3.x.
  * After the merge of this pull request, then we will start the upgrade Railsgoat to Rails 4.1.x.
Please do not merge yet. This is to share the work with the broader community. Please add comments or pull requests against my version for bugs/etc.
Thanks.