This was confusing translators as didn't make sense in English

And fix get_explicitly_set to use it and to get the json not native
field values.

It's a reasonable demo of in memory xblock creation, but doesn't fit
the xblock pattern. Moving temporarily to keep the dag persistence test.

Letting xblocks handle scope rather than separating fields into
different attrs. Although, split still shunts content fields to a
different collection than setting and children fields.

The big difference is that content fields will always be a dict and not
sometimes just a string and there's no special casing of 'data' attr.

The other mind change is no more 'metadata' dict.

change over the modulestore configuration to be a dict and use a property accessor. Also update some django-admin configs to use this means to set the runtime configuration

add a set_modulestore_configuration to the modulestore interface. This can be used to pass in settings run the Django tier

The django_nose it is very useful, even outside the test
environment. For example, it lets you to easily run test from
manage.py without additional changes to the test packages.

Better wording of commit

Workaround for issue

Better wording of commit

Fixed spacing

Also clarifies the contraction of location.course_id by throwing an exception for lcoations that are not of category course.

Add test for course_id method.

Features coming down the pipe will want to be able to:
* Refer to enrollments before they are actually activated (approval step).
* See what courses a user used to be enrolled in for when they re-enroll in
  the same course, or a different run of that course.
* Have different "modes" of enrolling in a course, representing things like
  honor certificate enrollment, auditing (no certs), etc.

This change adds an is_active flag and mode (with default being "honor").
The commit is only as large as it is because many parts of the codebase were
manipulating enrollments by adding and removing CourseEnrollment objects
directly. It was necessary to create classmethods on CourseEnrollment to
encapsulate this functionality and then port everything over to using them.

The migration to add columns has been tested on a prod replica, and seems to be
fine for running on a live system with single digit millions of rows of
enrollments.

cleanup.