* updated the flags for social media sharing
* added facebook feed ui to share public url
* update the condition logic
* update the code as per suggestion and added pick new style for share buttons
* update the css class reference
* update the bok-choy test
* updated description and some text touch-ups
* moved the JS related to facebook into separate location
* js formatting
* Add trailing comma per chrisndodge
* Add wait to fix flaky test...maybe

* Remove m2m relation between credit course and credit providers.
* Separate eligibility and provider APIs into different modules.
* Add API call for retrieving a user's eligibilities.
* Cache credit course list.
* Style the dashboard purchase button.
* Display a link for the credit provider on the dashboard.
* Add analytics events for clicks on the purchase button.
* Expose more credit models to Django admin and add search functionality.

(SOL-776)(SOL-740)(SOL-532) Added setting flags for COURSE DISCOVERY feature; Exposed course search input as well as the course result page; Added flag for limiting the number of course cards on the homepage;

repairs https://openedx.atlassian.net/browse/TNL-2007 and https://openedx.atlassian.net/browse/TNL-2009

Original Commit Messages:

Update ccx dashboard display to match new course display

Fix display of CCX dates on dashboard to use dates from the CCX instead of the related course.

The fix is implemented by providing date- and course-related APIs on the CCX object itself.  These APIs are mimicked from the same APIs available on a course descriptor.

bring the methods for printing start and end datetimes into line with course by adding UTC under the proper circumstances

add test coverage for new APIs defined on the CCX model

fix quality violation

TNL-1516

Combine sentences in several pages for better translation.

Remove duplicated course listings template code on the student dashboard.

Final official name is Custom Courses for EdX (CCX), rename all code to remove previous name.

Rename the FEATURE constant used to identify this feature

Rename the middleware for the CCX change

rename the constant used for storing the current poc id on the session.

rename the _PocContext threading local

rename the override provider in all places where it is referenced

`PersonalOnlineCoursesOverrideProvider` -> `CustomCoursesForEdxOverrideProvider`

generally rename symbols from overrides.py to replace `poc` with `ccx` where possible without changing model names or attributes

rename more symbols from poc to ccx
rename util functions from app utils module

general symbol renaming poc -> ccx in views.py and related url changes

Rename the coach role wherever it is used.

reword poc_coach to ccx_coach

UI rename

replace POC with CCX globally

template context variable renamed

rename poc_ to ccx_ in urls and all related locations (views, js, scss etc)

remove pocs migrations

Final massive renaming, including models.  Re-built migration.

cleaning up a few tailing references

Fix reference typo in schedule template JS

undo modifications made on the fly in test setup to ensure that our tests are properly isolated from the rest of the system tests.

Fixes jazkarta/edx-platform#38

Clean up some leftover strings and comments

fixing more strings and comments in python files

fix a naming error in the schedule tab that was causing problems in deleting courseware items.

Fixes jazkarta/edx-platform#36

updating tests and utility code to match changes in infrastructure from latest rebase

Show the display name for the POC in the menu for switching.

Remove the MOOC: prefix from the MOOC title to avoid truncation issues.

Incorporate the display name of the POC into the display of course org/number/name at the top of the page in the default theme.

Provide warning on the grading policy page in system warning style.

Provide a PocMembership model api that returns PocMemberships for a user.  Default to active memberships.

Build generator that yields triplets of poc, membership and course for each poc membership a user has.

This is an analog of the `get_course_enrollment_pairs` in common/djangoapps/students/views.py and is used in the student dashboard to provide pocs as options for a student to view.

refactor to use model api instead of inline code.

provide pocs as possible targets for a student to visit from their dashboard.

Unset the current active poc when visiting the dashboard so as to avoid needing to switch active pocs when viewing a plain course.  This ensures we can leave template code for the display of courses unchanged.

Update templates to show pocs in a course-like view on a student's dashboard.

Revert a portion of the template change so that the poc title will still render properly when a poc is being viewed.

- reversing the positions of the sidebar and course listing
- html for new social icons (not currently wired up)
- new actions dropdown for unenrollment and email settings
- partial reorganization of dashboard.scss styles
- text fix for unenrollment
- added missing endif, p/hgroup closures
- reverted la.course-item
- removed extra operator
- fixed broken bok choy test

On student dashboard currently there was currently no main region landmark.
So added the role with the main conents of the dashboard.

TNL-1567

Users who are blocked from enrolling in a course
due to an embargo are redirected to the blocked
message page after authentication completes.

fieldset element was unnecessary and input fields were not
associated with their parent label

TNL-1076

* updating vendor files
* updating class syntax (to new FA-based classes) for all UI elements
* correcting broken tests

WL-172 Show a Order History list on the Student Dashboard for any PaidCourseRegistration or RegCodeItem that the user might have purchased

Change third party auth login failure code to a 401, to detect authentication
success with no linked account.

If already authenticated, redirect immediately to the dashboard.

Use "Location" header correctly for 302 redirects from student views.

Add utility functions for simulating a running third-party auth pipeline.

Add a utility function for checking whether third party auth is enabled.

Respect default values sent by the server

Make HTML comments Mako comments

Make donations configurable

Added donation button to dashboard

Generalize merchant defined data for payment processor

Change the reverification failure message styling.

Changing templates so new styles do not appear in courseware.

Removing unused aria tag.

PR comments on cleaning up SASS

Fix signup LMS test.

Copy changes per review on PR

Updating based on PR comments

Style and HTML changes for notifications