burndown schema migrations (#1727)
Merge pull request #2015 from Stanford-Online/sef-1727-migration-burndown

burndown schema migrations (#1727)
Minor clean-up for Save Answers error path

Add supplemental text if it exists, store unsaved data in localStorage
so it won't be completely lost in all cases. TODO: Add more robustness
here

	modified:   templates/exams/view_exam.html
Merge branch 'master' of https://github.com/Stanford-Online/class2go into wescott-master-exercise-work