exam_edit: initial checkin (#2459)
exam_edit: option parsing and validation (#2459)
exam_edit: parse setters (#2459)
exam_edit: value conversion and assignment (#2459)
exam_edit: use django's update, much cleaner (#2459)
exam_edit: remove conversion function, using django's now (#2459)
Merge pull request #2467 from Stanford-Online/sef-2459-exam-edit-command-prod

Exam bulk change management command (#2459) -- PROD