Please note that this is a squshed commit and the work of:
Symbolist, macdiesel, nedbat, doctoryes, muzaffaryousaf and muhammad-ammar

Add context for navigation states
added find course to dashboard sidebar and included check for context that Will adds in PR
removed nav_course_search context due to design change so replaced with nav_hidden
Removed rwd_header.js and all references as no longer being used.

Wrapped Find Courses in dashboard sidebar in if statement

* Delete reverification templates
* Delete photocapture.js
* Delete unused "name change" end-points
* Rebuild the reverification views using Backbone sub-views
* Stop passing template names to the JavaScript code
* Avoid hard-coding the parent view ID in the webcam view (for getting the capture click sound URL)

* Adds a credit course mode to indicate that a course
has a credit option.

* Hides the credit option from the track selection and
pay-and-verify pages.

* Shows different messaging for the verified track if
it's possible to upgrade from verified to credit at the end
of the course.

Block users from enrolling in a course if the user
is blocked by country access rules.

1) Enrollment via the login/registration page.
2) Enrollment from the marketing iframe (via student.views.change_enrollment)
3) Enrollment using 100% redeem codes.
4) Enrollment via upgrade.

This does NOT cover enrollment through third party authentication,
which is sufficiently complex to deserve its own commit.

Removes old payment and verification endpoints, views, templates, and tests, making the new split flow the default. The SEPARATE_VERIFICATION_FROM_PAYMENT feature flag is also removed.

Adds mode creation endpoint to course_modes app and ability to bypass media device access prompt when proceeding through verification flow in a testing environment.

Allow disabling of experiment

Set marketing site logged in cookie from third party auth.

The body of the enrollment message template

Tokenize platform name in message.

Changing to a datetime enrollment approach

Adding sorting. A little refactoring.

Adding confguration model for time delta

Adding admin registration and basic form for new config model.

Fixing docstring typo

Updating default time delta to 0, adding test to show it disabled functionality.

Removing the form from configuration and tweaking the enrollment message html

which raise IntegrityErrors.

TNL-367

Update devstack settings to use new CyberSource API

Add session middleware to an external auth test to fix a test failure with the auto-registration AB-test changes

ECOM-41

- Changes registraiton button text for professional ed courses
- Professional ed courses do not see "choose your track" page; go straight to verification flow

- Changes registraiton button text for professional ed courses
- Professional ed courses do not see "choose your track" page; go straight to verification flow

Fixes LMS-2830

Remove course_from_id
don't fetch whole course when the root will do
don't fetch even the root if the id will do
check for definition.data == null

[LMS-2757]

This commit updates common/djangoapps.

These keys are now objects with a limited interface, and the particular
internal representation is managed by the data storage layer (the
modulestore).

For the LMS, there should be no outward-facing changes to the system.
The keys are, for now, a change to internal representation only. For
Studio, the new serialized form of the keys is used in urls, to allow
for further migration in the future.

Co-Author: Andy Armstrong <andya@edx.org>
Co-Author: Christina Roberts <christina@edx.org>
Co-Author: David Baumgold <db@edx.org>
Co-Author: Diana Huang <dkh@edx.org>
Co-Author: Don Mitchell <dmitchell@edx.org>
Co-Author: Julia Hansbrough <julia@edx.org>
Co-Author: Nimisha Asthagiri <nasthagiri@edx.org>
Co-Author: Sarina Canelake <sarina@edx.org>

[LMS-2370]

LMS-1384

LMS-1127