EDUCATOR-44

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

Added course level lang attribute for LMS

added lang attribute to Studio

fixed error when trying to get language attribute on course that does not exist

simplified code

added lang attribure to more places in LMS, added migration for language attribute in course_overview

fixing contraints in the database for language attribute

added lang attribute to several more places in LMS and Studio

added lang attribute to discussion and custom pages; cleaned up code

fixed issue that was causing test failures

moved lang attribute higher in tree in two places

EDUCATOR-563

EDUCATOR-396

This reverts commit f97f0525, reversing
changes made to 800bcd8e.

https://openedx.atlassian.net/browse/EDUCATOR-389

TNL-6743

incoming scores.

TNL-6697

TNL-6746

TNL-6744

TNL-6674

Add i18n to backend error messages in case they appear to end user
Remove success banner when trying to publish or discard changes on container page

This reverts commit 83f2be49, reversing
changes made to 01ed1742.

Fixed Backend: Move component directly to content experiment level (component will now be the sibling of groups)

Fixed Move button is disabled when moving components inside conditional module

Fixed When navigating upward/backward, target parent is not set correct, resulting source to be moved in the previously selected parent

Introduces a mgmt. command that retrieves course runs from catalog service in order to update marketing urls for the courses found in course metadata cache (i.e. CourseOverview). This also provides an updated utility to retrieve course sharing url.

TNL-6628

This is unused, and will no longer be supported on edx.org. Also adds a
DeprecatedModel utility class.

TNL-6126

TNL-6060