Added api/assignments/:id/groups
Cleanup main api controller comments
Update SubmissionDownloadsController
Created tests for controller, and also fixed a bug in
submission.rb's get_submission_by_group_and_assignment
MainApiController should render 404's for all routes by default
Simplify GroupsController
Merge pull request #1062 from danielstjules/issue-1002

Issue 1002: Add groups controller, update submission_downloads
FIX for issue 1029, add indicator for new annotations from remarking
Merge pull request #1063 from m-wu/issue-1029

Add indicator for new annotations from remarking.
Closes #1029
Fix: tests with remark request
Merge branch 'master' of github.com:benjaminvialle/Markus into machinist2
Merge branch 'tests' of github.com:benjaminvialle/Markus into machinist2