Add comments to progressions_graph_controller action methods and private methods.
Allow in-line editing of bar chart pieces and live updating on save.
Clean up progression_graphs controller routes to use nicely formatted
URLs, rather than query strings for the id.
Add js-routes GEM to expose URL helpers as named functions in JavaScript.
Allow in-line editing of pie slices and live updating on save.
Add rspec and factory_girl_rails gems to support rspec with factory girl factories.