Add lots of files
Navbar fix
Update controllers
Add terms creation
Modify navbar
Add maintenance
Filter groups when create an assignment
Sort groups/courses in navbar
Better course/terms route
Minor bugfixes
Fix students_controller
Fix tasks adding when new student subscribe to term
Modify models
Add more db associations to tasks
Remove group select input field from registration form
Delete unwanted assets
Prevent creating assets with new controller
Clean html for problem fields in 'homeworks#new'
Fix mailers
Add 'teacher_id' to submissions in 'submissions#create'