add new exam jsons
Checks properly for existence of array element for quiz_log response_log.
Merge pull request #2300 from rtibbles/quiz_log_fix

Checks properly for existence of array element for quiz_log response_log
bring back the old seeds for the baseline exams, as some teachers have already tested for it
Increase minversion on description field to ensure removal, and don't hash.
Merge pull request #2306 from learningequality/nalanda-rct2

Nalanda rct2 into central-master