Merge pull request #2280 from learningequality/nalanda-rct2

Nalanda rct2 to nalanda
Merge pull request #2304 from learningequality/nalanda-prerelease

Nalanda prerelease into release
Merge pull request #2319 from learningequality/nalanda-prerelease

Releasing recent Nalanda fixes
Merge branch 'nalanda-rct2' into nalanda-prerelease
Merge branch 'nalanda-prerelease' into nalanda
Merge pull request #2341 from learningequality/nalanda-rct2

Release Nalanda RCT2 updates
Merge pull request #2342 from learningequality/nalanda-prerelease

Nalanda prerelease
Merge pull request #2412 from learningequality/nalanda-rct2

Nalanda rct2 to nalanda rct3
Prevent students from changing their group
Add `mimeparse.py` from `nalanda-rct3` because `tastypie` needs it.
Add browser tests for group selection on facility user form
Merge pull request #2418 from dylanjbarth/2414-student-groups

Prevent students from changing their group
upgrade selenium from 2.39.0 to 2.43.0
add `ghostdriver.log`
Merge pull request #2429 from mrpau/feature/upgrade-selenium

Upgrade selenium from 2.39.0 to 2.43.0
Merge branch 'release-0.12.0' into hotfix/add-mimeparse-py
Merge pull request #2420 from mrpau/hotfix/add-mimeparse-py

Add `mimeparse.py` from `nalanda-rct3` because `tastypie` needs it.
Merge pull request #2432 from learningequality/release-0.12.0

Release 0.12.0 to nalanda-rct2
Sign Up Link Issue 2427
Merge pull request #2453 from anuragkanungo/nalanda-rct3

Sign Up Link Issue 2427 Fixed
Issue 2439 Login/Signup page opening even already logged in fixed