LEARNER-877

[ENT-370] Update Support Link on Sign In Page

LEARNER-1101: Add best practice doc for course overview/course blocks.

Enrollment attributes are now always stored, regardless of whether an enrollment is being created or updated. This will ensure that learners who purchase paid modes, without first enrolling in a non-paid mode, can request refunds if they choose to un-enroll from a course run within the refund window.

LEARNER-1282

Lower safe lint thresholds.

Bump edx-celeryutils to 0.1.4

Defaults to SUPPORT_SITE_LINK intentionally.
Also fixed surrounding quality tests, and overall
quality improvements.

Correct activation email support link defaults in views.py

bump LTI Consumer XBlock to latest version

LEARNER-1279: Revert: Course jump tos should go to the main course home page.

update ORA2 to 1.4.1

[ENT-386] Styling Issues on new registration page

[ENT-378] Remove code for custom header logo

EDUCATOR-62 Fix question text wrapping in IE11

Add instructions.

LEARNER-859: Updating styling on the course updates page

Revert commit: c14f0b14

Mark test as flaky, and remove flaky from a fixed test.

Fix for LEARNER-859: Updating styling on the course updates page to more clearly differentiate between multiple updates. Specifically:
- Updated styling on date in the top left corner
- Added horizontal line between updates
- Removed ability to toggle updates on and off
- Cleaned up code to always show all updates:

LEARNER-881: Per-course rollout configuration model

EDUCATOR-511

More specific grade_course logging

Sstudent/course policy event

More celery logging

Mask grades on progress page according to show_correctness setting

Fix the activation email support link in the dashboard sidebar

Defaulting to a plaintext response makes no sense for an endpoint that is intended to be used by machines for testing. The endpoint now returns JSON only unless a redirect action is triggered.