Putting the new edx header behind a feature flag.

updating the version for django_countries

Clean up shopping cart processor API.
Fix UUID JSON serialization bug in CyberSource2 implementation.
Update test suite to use new CyberSource2 implementation.
Fix i18n messages in CyberSource2
Enable CyberSource2 implementation by default.

LMS-11181

Make default_store thread-safe.

- adding comments

 - spacing issues and indentation

STUD-1725

Currently a new temp directory is created for every process via
mkdtemp_clean() which cleans it on process exit.

However, this is not compatible with using --preload option of
gunicorn. With this option the tmp directory is created on gunicorn
start and is shared by all the workers. But when a worker exits it
deletes the directory. And so on the next requent the tmp directory
needs to be recreated and the templates need to be recompiled.

LMS-6507

The same bug in studio was fixed in #3893, and as TinyMCE is also used in LMS, it should be also fixed in LMS.
Here a common javascript file called 'ie_shim.js' is added, so that in the future it can be used for other IE compatibility purposes too.

Move modulestore django settings migration code down into the modulestore layer so it works for all django-based callers.

Filipino, Marathi, Serbian, Telugu, Uzbek

Add filter to only show first occurance of DepWarning

LMS-2651

Refactor get_parent_locations STUD-1663

Added ORA2_FILE_PREFIX setting

Making sure extension comes after annotator css

- UI Fixes for Diacritic Mark Plugin