* remove unenroll for masters

* i18n string

dashboard.

    CourseOverview

    This line of code will cause a failure in the retrieval of the
    CourseOverview get_from_id method because it attempts to load with a
    string rather than a CourseKey.

Pass in a CourseOverview object instead of expecting that passing id will work as expected.

PROD-799

Dashboard is set to load 250 courses instead of
all the courses. A flag is also added to change
the number the courses to load.

PROD-204

- Add announcements view using JSX to the dashboard sidebar
- Create a new maintenance interface to edit and manage announcements
- Adds an override to main.html template to include new skip links
- Add plugins required for announcements to TinyMCE

This is motivated by a desire to have system wide messages for students
that show on the dashboard. Enabled with FEATURES['ENABLE_ANNOUNCEMENTS'].
Global staff are allowed to edit from the studio maintenance view.

for experiments.

REVEM-174

Django 1.10 deprecation fix for Hackathon XIX
Addresses PLAT-1397

if HIDE_DASHBOARD_COURSES_UNTIL_ACTIVATED is enabled.

(cherry picked from commit 761acdfc)

When set, displays the configured text/markup under "You are not enrolled in any courses yet."

Adjusts left/right padding on .empty-dashboard-message to keep our extra message from hitting the sides.

(cherry picked from commit e417c5f8)

Site Configuration and feature flag

When set, it hides the Courses list on the Learner Dashboard page if the
learner has not yet activated their account.

(cherry picked from commit 22ee400b)

learner-4715

Updates behavior post unenrollment, also refactors accessible_modal
to enable the unenrollment survey to remain accessible after the
content in the modal changes (to the survey).

mloturco/learner-3524

if HIDE_DASHBOARD_COURSES_UNTIL_ACTIVATED is enabled.

When set, displays the configured text/markup under "You are not enrolled in any courses yet."

Adjusts left/right padding on .empty-dashboard-message to keep our extra message from hitting the sides.

Site Configuration and feature flag

When set, it hides the Courses list on the Learner Dashboard page if the
learner has not yet activated their account.

Needed to rearrange the label of the checkbox

LEARNER-4230

LEARNER-3808

Ensures that users can see their entitlement purchase whether there
are available sessions or not. Notifies them with a message stating that
more sessions are coming soon, as is currently implemented on the programs
dashboard.

The dashboard was not showing related programs for expired but
fulfilled entitlements.

LEARNER-3608

LEARNER-3304

Displays the expired out status for the course dashboard and the programs pages.

LEARNER-3438

The user can now enroll in a session, unenroll from a session or change session
from a new course enrollment card on the programs dashboard.

On the course dashboard, show related programs to your course
even if you are not enrolled in a current session.

LEARNER-3504

The user can now enroll in a session, unenroll from a session or change session
from a new course enrollment card on the course dashboard.