LMS: add CSRF token to register form
Add Neurolit to AUTHORS file
Set empty aws credentials to None.
Changed create_enrollment to create_or_update_enrollment
all CourseEnrollment modifications route through create_or_update
purchased_callback now uses the change_mode method
Studio: resolves IE notifications display issue and abstracts CSS to avoid IE selector/rule limit
STUD-815
more granular transactions in grading [LMS-1480]

remove field_data_cache from grades.grade and grades.progress_summary

cleans grading code by adding wrappers
Merge pull request #1655 from edx/adam/more-granular-grading-transactions

Adam/more granular grading transactions
Persist student answers on input error

LMS-469
Revert: Allow any part of protocol name to be lowercase or uppercase.
Merge pull request #1659 from edx/hotfix/revert-transcripts-protocol-validation

Revert "Don't allow users to enter video url's in http."
Fixed bug where Flash photo taker would fail

LMS-1487
Removed unused code
pep8/pylint fixes for capa
Disabled test making external calls to YouTube
Merge pull request #1665 from edx/will/disable-transcript-youtube-test

Disabled test making external calls to YouTube
Fix for advanced settings failure
Revert "more granular transactions in grading [LMS-1480]"

This reverts commit 19dd49f35510f9713899534e049edbf1ffe1250a.
Merge pull request #1669 from edx/hotfix/revert_grading_manual_tx

Revert "more granular transactions in grading [LMS-1480]"