Created migration deleting field from db elements
Parser is now using the new property abstraction
Program index view is now handling the new property abstraction
Catalog is now created even is no graph xml file is given by the user
Refactored Catalog Controller (moved upload logic into the model)
Shallowed nested resources
Updated view to match shallowed resources nesting (+ fixed minor bug in sub_module creation
Fixed polymorphic routes for courses (in a nice way \o>)
Updated Course Destroy Function to work with his 3 possible parents
Course New & Create action are now creating their properties
Added download action into catalog controller