[JRO] Get posts to render

Copy over the post views and start working on cleaning them up.

* Introduce a PostDecorator to clean up view
* posts/user and posts/null_user partials
* auto-load decorators dir
* Add to_s to User class
* Add some documentation in README to get parent app set up
[JRO] Users are able to create topics

Ported cucumber features from old main app to rspec+capybara. Cleaned up
some things during the move but mostly to get the feature(s) passing.

* Copy posts view partials over from the main app, cleaned up
* require nested_form to get working
* Bug in topic_user_permissions were not allowing a logged in user to
  create a new topic on a public messageboard. Fixed.
* Remove all observers from the app.
* Add Topic#decorate and Topic.decorate will run an object, or
  AR query through the topic decorator. Ok Cool.
* Clean up the views