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
Merge pull request #2301 from learningequality/nalanda-rct2

Nalanda rct2 into nalanda-prerelease
bring back the old seeds for the baseline exams, as some teachers have already tested for it
Merge pull request #2302 from learningequality/nalanda-rct2

bring back the old seeds for the baseline exams, as some teachers have a...
Merge pull request #2304 from learningequality/nalanda-prerelease

Nalanda prerelease into release