Refactoring tree_display views
Fixed path and refactored another file
Refactored courses_folder_actions route helpers
Merge pull request #4 from stefanjf/routing_helpers_2

Refactoring tree_display views
Made more CRUD-like and made associated changes to seeds.rb and added migration.
Update more path helpers for tree display views
Change migration logic - create new index controller action and delete all others with tree_display site_controller
Change form to use GET request so that index is used
Add groups hash to convert session variable names to database label syntax
Delete some comments and fix general tree_display view (session var)
Revert drill route, fix helpers/params
Correct previous routing helper change
Update hashing syntax (remove rocket operator)