TNL-5240: Cache comment thread.

AC-581 using UXPL values for course types on dashboard

Merge release into master

Cache Enrollment state for (user, course) in request cache

patch/2016-09-12

Fix RTL issues with discussion sass

logging

Enable Persistent Grades in unit tests

TNL-4709

Fix extremely minor box corner issue in Discussions

Catalog-based MicroMasters need to be displayed in the LMS. However, the LMS currently retrieves all program data from the soon-to-be-retired programs service. Consuming program data exclusively from the catalog service is out of the question right now; it's too complex to confidently pull off in a week. This is a functional middle ground introduced by ECOM-5460. Cleaning up this debt is tracked by ECOM-4418.

Enable discussion forums on CCX courses.

Discussion is restricted to the CCX course (there is no sharing of
discussions with the parent course or other CCX instances).

Ensure usage keys have course run in locators.

TNL-5475

Optimize Subsection Grades update

TNL-5457: Performance enhancements for Discussions API.

- Default to with_responses=False, except when required.
- Clean up search call unused params.

Fix width of 'Load More' button in Discussions

Update xblock-poll dependency to v1.2.

Fix bug where new posts were not assigned a topic ID and would fail to post

Persistent Grade being saved for individual problems

* First take at forcing a subsection's grade to update when a signal is
  sent that a problem's score has changed
* Refactor signal handler connection.
* Expand bokchoy tests to cover progress page
* Add some grading unit tests

TNL-5394
TNL-5364

Pass Sailthru campaign id cookie to ecommerce

[ENT-13] Make SSO providers optionally hidden

TNL-5442

TNL-5404: Default to not requesting responses when grabbing a single thread.