update_course_in_cache should retry on exceptions

Recalculate Subsection Grade task retry logic

Make problem block tests more realistic.

Includes:
* CAPA
* ORA
* LTI
* LTI-Consumer
* SGA
* Randomized Content Block

TNL-5692
TNL-5464

byte-size fix for 2 lines page navs

Add support for additional answers for Numerical Input problems

TNL-5581

Convert problem/edit.coffee to JS

Previously, retry() was never called, so the task was never retried despite
defining several retry-related variables.

add grading policy hash to transformer

Adjust lint thresholds

Allow Celery queue settings to be defined by ENV_TOKENS

Fixed authentication classes to support Django OAUTH Toolkit

The task will now be retried if an IntegrityError is encountered, up to
the default of 3 times. Test included.

TNL-5739

Upgrading django-storage-swift module to take advantage of pending PR

ENT-28: Add testing for 'saml' management command

Update DnDv2 to v2.0.11.

ECOM-5846 Add more logs for enrollment api

Add enable-migrations parameter for python unit tests

Fix Malformed Staticbook url

Merge Release to Master

Release Candidate rc/2016-10-18

Fix Moldova spelling on dropdown list

Removed unnecessary http:

Fix flaky test: test_youtube_id_w_different_local_server_sub

Fix screen-reader capa status prefixing

Remove invalid selector

[TNL-5632] Don't request responses/comments for non-AJAX requests.

Firstly, we're now explicitly instructing the comments service to not
return thread responses/comments if the request isn't AJAX.  So, if you
load the URL for a single discussion thread in your browser, this would
be a non-AJAX call and we'll avoid loading the responses for the entire
thread behind-the-scenes.  Big win here for large threads.

Next, we removed a redundant "get threads" call which was also happening
behind-the-scenes.  This call was redundant as the front-end JS also
grabs the thread list when a topic is chosen, so we were making an
extranenous call for no benefit.  Poof, gone!

Finally, we added some caching of database queries that are required to
drive a lot of the permissions/cohorts machinery around discussion.
This will have a minimal effect but introduced a cleaner way to apply
general memoization at the per-request level which will let us further
cache things as we identify them as issues.