Added CRUD operation for sub_module
updated .gitignore file
Removed useless stuff in /seeds/ (again)
Implemented Course#new, Course#index and Course#edit to match new SubModule object (nasty but working :s)
Parser is now handling sub_modules
Updated todolist
Parser is now parsing n-ary constraints
Created constraint model
Parser is now creating n-ary constraint (Remaining bug with xor - nary relation
Refactored Insert Constraint Method of Parser