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
add khan_api_python from upstream/hackathon
Add filter 'compute_percent' to custom templatetags in fle utils
Merge branch 'central-master' of github.com:learningequality/ka-lite into central-master
Merge pull request #2362 from learningequality/central-master

Central-master into Nalanda-RCT3