LEARNER-1798

PLAT-1499 Use appropriate default settings in Docker devstack

Reduce xss thresholds.

Add flag to configure whether "Notify users by email" is checked by default.

Keep button shape for long strings

Removed old (unused) devplus.py env for LMS.

Override video xmodule's youtube id with the id coming from val YT profile

Implement a skeleton page with Bootstrap

LEARNER-1174

This used to be where we enabled some prod-like features on the dev
environment, but it's horribly out of date (it actually predates
the vagrant-based devstack).

Do not capitalize words in start button

Learner-1146

Fetched Programs and Program details from Course Discovery service for all sites and stored the uuids in cache with site-specfic keys.
Learner-1146

Replace urls in html updates.

Bump up the NewRelic plugin version

Most bugfixes are python3 or Tornado specific, but several releate
to Django 1.10 and they improved transaction traces since we last
updated.

https://docs.newrelic.com/docs/release-notes/agent-release-notes/python-release-notes/python-agent-286370

[ENT-457] Fix failing course_mode tests

fix issue where video modal is not closed by clicking outside the video

Rename xss linter.

Change to validate=False which emulates django-storages

[ENT-457] Create EnterpriseCourseEnrollment when enrolling via Track Selection page

This requires the next commit to work, but needed to be
is a separate commit to keep history.

eslint config edx v3

On many buckets, we use s3://bucket/path to separate environments
because AWS used to have a really low limit on the number of buckets
we could have, and we wanted to share them across environments.

If you combine this with an IAM policy that only allows you access
to the s3://bucket/path that you "own", then get_bucket fails.
http://boto.cloudhackers.com/en/stable/ref/s3.html#boto.s3.connection.S3Connection.get_bucket
The HEAD appears to be similar to get_all_keys which requires
ListObjects on the bucket with no conditions.

django-storages (Which is what we write new S3 access in) actually
always passes validate=False unless you're allowing it to create buckets
for you (which we never do).
https://github.com/jschneier/django-storages/blob/1.4.1/storages/backends/s3boto.py#L320-L334

EDUCATOR-793: converts TypeError,NotFoundError logging to debug only

LEARNER-1604: Change default and refactor old unified_course_view flag.