Merge pull request #2292 from learningequality/nalanda-rct2

Nalanda rct2 to central-master
Merge pull request #2301 from learningequality/nalanda-rct2

Nalanda rct2 into nalanda-prerelease
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 #2306 from learningequality/nalanda-rct2

Nalanda rct2 into central-master
Merge branch 'nalanda-rct2' into central-master
Merge branch 'nalanda-rct2' of github.com:learningequality/ka-lite into central-master
Merge branch 'nalanda-rct2' into nalanda-prerelease
Merge pull request #2318 from learningequality/nalanda-prerelease

Nalanda prerelease to central-master
Merge branch 'release-0.12.0' of github.com:learningequality/ka-lite into central-master
add object admin authorization for api auth
Fix authorization for CSV export for central server
Adding auth and first pass zone level csv export.
Rework backbone code to 1) work and 2) disable options dynamically
Fix bug in resetting disabled attribute
Add FacilityUser endpoint
Add CSV serializer and endpoints for AttemptLog and testLog
Works for central server, added styles.
Add "virtual" fields to FacilityUser resource
Return empty CSV if no objects match query
Exclude extraneous info for attempt and test log CSV responses