An issue arose recently due to ATOMIC_REQUESTS being turned on by default. It
turns out that CohortMemberships had been somewhat relying on the old default
transaction handling in order to keep CohortMemberships and the underlying
CourseUserGroup.users values in-sync.

To fix this, I've made all updates to Cohortmemberships go through an
outer_atomic(read_committed=True) block. This, is conjunction with the already
present select_for_update(), will no longer allow 2 simultaneous requests to
modify objects in memory without sharing them. Only one process will be
touching a given CohortMembership at any given time, and all changes will be
immediately comitted to the database, where the other process will see them.

I've also included some changes to get_cohort(), add_user_to_cohort(), and
remove_user_from_cohort() in order to properly make use of the new
CohortMembership system.

Modify existing Programs migration to account for help_text change

SOL-1417 Certs: Allow CSV upload for Cert Exceptions

Add pagination support to course catalog API

SOL-1389: Cert Exception: Add error states and messages

Support multiprocess bok-choy testing for discussion

SOL-1439: removed certificates delivered dependency on certificate eligibility

SOL-1466: Make sure web view renders certs only if downloadable.

* Catalog results are now paginated
* Implements the new namespaced pagination described at
  https://openedx.atlassian.net/wiki/pages/viewpage.action?pageId=47481813
* API level code returns pythonic business objects
* View layer performs serialize at the view layer
* Convert views to use DRF generic views
* Removes an unintentional authentication decorator that caused
  the detail endpoint to return a 401 for anonymous users

MA-1724

MA-1211; Discussion API - make boolean params case insensitive

Do not install xblock-utils in editable mode

split variables on multiple lines

changes after feedback from Afzal

Aamir khan/ecom 1447 login error message

Prevents makemigrations from creating a new migration for the programs app.

Initial migrations for verified deadlines for self paced

Sprint Solutions:Zug PHX-200 PHX-201 Adding LTI consumer XBlock to requirements

MA-1667: Update Mobile API to support Web Certificates

Suggest the devops group alias, rather than individual names

OwnLearnerProfile multiprocessing support

Make cohort management tests multiprocess capable.

This fixes a flaky condition that is only exposed when
tests are run in multiprocessing mode.

Fix a flaky test condition that only occurs in
multiprocessing mode. Make the page definition more
specific; the previous implementation would not fully
render all objects in time.

Avoid race condition related to events order (in faster,
multiprocess testing, the order is not exactly the same since
some events arrive at once).

Add scenario for testing unicode cohort.

Verifying the events is a TODO because the verification method
will need to be refactored to handle an additional cohort
that's not included in setUp. (Or refactor the setup, or refactor
the unicode test, etc.)

Help text update for full name

LoggerBackend encoding for json dumps

Fixed test create library failing on chrome

Migrations will now run during Acceptance tests

SOL-1433:remove audit course mode