This reverts commit 12130c80.
Manual testing found this to not fix the bug it claimed to fix.

CohortMemberships minimal fix

What had been happening was related to the fact that ATOMIC_REQUESTS is now on,
preventing writing to the database until a request is completed.

The problem with that was that CohortMemberships, with their explicit
transaction handling, were breaking that rule and touching the database.
The CohortMembership needs to also touch the database to update the
underlying course_user_groups information, to prevent the database from
getting into a strange state.

After this commit, every time a CohortMembership is updated or created, the
corresponding course_user_groups are also updated and explicitly written to
the database. This occurs atomically with the CohortMembership, and does not
wait for the end of the request.

Upgrade ORA version to fix staff tools styling

Upgrade to Django 1.8.7

Use edx-proctoring 0.11.6

DOC: Studio Help -- update config.ini file with new paths to B&R Guide

remove unneeded aria-describedby and aria-hidden attrs on studio modal

Added new Course Catalog API

https://openedx.atlassian.net/browse/MA-1625

Update translations (autogenerated message)

Overridden start and due dates of problems to control due date of a unit from ccx schedule

Use the latest ORA and submissions API

Cdodge/fix zero seat invoices

Add the Microsoft Office Mix XBlock

fix quality error

Merge pull request #10658 from edx/ahsan/ECOM-2897-Update-help-text-for-Name-field-in-edx-registration

Update help text for Name field in edx registration

GitHub has a capital H

Use 0.1.4 of i18n-tools so Django 1.8 will work. PLAT-919

Add in the attempt_code field to the proctoring report

ECOM-2897

Fix pylint C7630 (literal used as attribute) violations

Upgrade to latest 2.x version of pymongo.

There's no need to use a string literal in setattr, delattr, or the
two-argument form of getattr.

Navigation dropdown link should be button 

Release Notes: https://jira.mongodb.org/secure/ReleaseNote.jspa?projectId=10004&version=14795
Mostly backports to prep for moving to 3.0

remove reset style for button outlines in firefox

Update the django-wiki reference