Replaced a test by the relevant model method
Bug fix for issue #1056
Added feature related to issue #230 only for admin (404 error with grader)
Added a unit test stub for SubmissionsHelper
Corrected test stub for SubmissionsHelper
Made section collection available for graders - issue #230
Merge pull request #1057 from Keraunos/Issue#230

Allow to collect all submissions for one section when the collection date for that section has passed
Closes #230