Hw updates rag/hw4_grader_stuff for Spring 2014 MOOC

- **Pull request on hw repo for bdd-tdd-cycle will depend on this.**

- Gemfile and Gemfile.lock: rails 3.2.16,  ruby 1.9.3, remove all other version specs, remove therubyracer

- movie.rb: added attr_accessible to allow mass assignment

- application.rb: added whitelist_attributes=true, initialize_on_precomile=false, active_support.escape_html_entities_in_json=true