add license to a11y_tools.js

add tests, some reorganization of js tests

skip "toBeFocused" tests for now

LMS-1310

The close button for the modal dialog was marked up as a paragraph,
containing a graphical text character, inside two div elements, with an
associated click event. This made the button unusable for keyboard
users.

Replaced <divs> with a link element (<a role="button"), adapted the CSS
accordingly, and updated the existing <a> modal close buttons.

Some minor pep8 cleanup

Switch to using decorators; refactor and cleanup tests.

Adds a new Email link to the instructor dashboard for frontend interface to send
email to course members. Adds a feature flag ENABLE_INSTRUCTOR_EMAIL to toggle this.
Creates a new djangoapp bulk_email that handles this action by getting the recipient
list and batching the emails to different celery tasks to do the actual sending.
Requires lynx package to convert HTML email to plaintext. Handles SMTP errors by
retrying or falling through to the next email. Adds the option to opt out of course
specific emails in the user dashboard with an Email Settings link for each course.
Uses severable configurable settings with defaults. DEFAULT_BULK_FROM_EMAIL
specifies the from address for email. EMAILS_PER_TASK specifies the number of emails
each celery task takes on. EMAIL_HOST, EMAIL_PORT, EMAIL_HOST_USER,
EMAIL_HOST_PASSWORD, and EMAIL_USE_TLS for the SMTP email backend settings.

Co-authored-by: Akshay Jagadeesh <akjags@gmail.com>

fixes template errors

keep tos untranslated

formatting fixes

Remove unused course_filter page

removes university_profile urls and templates

removes all university_profile views

remove news from templates/index

Highlights:
* The url '/shib-login/' interfaces with apache/mod_shib via
  request.META to handle shibboleth login and registrations
* Courses can designate 'enrollment_domains' to limit enrollment
  to users with a linked ExternalAuthMap verified by a particular
  identity provider
* Tests
* Logging

 Changes to be committed:

	new file:   common/djangoapps/external_auth/migrations/0001_initial.py
	new file:   common/djangoapps/external_auth/migrations/__init__.py
	new file:   common/djangoapps/external_auth/tests/test_shib.py
	modified:   common/djangoapps/external_auth/views.py
	modified:   common/djangoapps/student/views.py
	modified:   common/lib/xmodule/xmodule/course_module.py
	modified:   lms/djangoapps/courseware/access.py
	modified:   lms/djangoapps/courseware/tests/test_access.py
	modified:   lms/envs/common.py
	modified:   lms/envs/dev.py
	modified:   lms/envs/test.py
	modified:   lms/templates/courseware/course_about.html
	modified:   lms/templates/dashboard.html
	modified:   lms/templates/extauth_failure.html
	modified:   lms/templates/navigation.html
	modified:   lms/templates/register.html
	modified:   lms/templates/signup_modal.html
	modified:   lms/urls.py
	renamed:    lms/wsgi_apache.py -> lms/wsgi_apache_lms.py

Remove the Stanford-specific if/else hack to set the appropriate
contact email address and use the `CONTACT_EMAIL` setting instead.

Again, most of the work here is replacing "edX" with the
`PLATFORM_NAME` setting. Need to ensure that the `news` boolean is
indeed a falsy value as well, or just add a `theme_enabled()` test
to disable the news block entirely (since news is an edX-specific
feature).

If a course is not started, the course image and title on the dashboard link
to the course about page. Because the LMS course about pages do not exist
(i.e. 404) with the marketing site enabled, we simply do not use a link if
the course has not started.

* Fix indentation/line break issues
* Handle marketing root URL as a separate case in marketing_link
* Move link map to its own setting.

and use it for the new marketing site links.