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
Response to CR
response to CR
Teach OEE to consider old task_states when trying to recover from an xml mismatch
Centralize to a single GradingServiceError, so that it's caught when expected
Small fix
Assign a score of 0 to tasks with no attempts
Use correct set of OpenEndedChild states
Merge pull request #1686 from cpennington/hotfix-max-empty-sequence

Assign a score of 0 to tasks with no attempts
BLD-193: Add template for checkboxes to studio.
Fixed password reset message

LMS-1507
Merge pull request #1688 from edx/anton/add-template-checkboxes

Add template for checkboxes to studio.
Merge pull request #1594 from neurolit/csrf_accessibility

LMS: add CSRF token to register form
Adding a YAML file to demonstrate how to include anonymized user IDs in Studio elements.
Basic test fix