Merge pull request #4720 from edx/split/add-and-fixes

cms/djangoapps/contentstore/features/video.py

...angoapps/contentstore/management/commands/check_course.py

cms/djangoapps/contentstore/tests/test_contentstore.py

cms/djangoapps/contentstore/tests/test_course_settings.py

cms/djangoapps/contentstore/tests/test_import.py

cms/djangoapps/contentstore/tests/utils.py

cms/djangoapps/contentstore/views/assets.py

cms/djangoapps/contentstore/views/course.py

cms/djangoapps/contentstore/views/item.py

cms/djangoapps/contentstore/views/tasks.py

cms/envs/bok_choy.auth.json

cms/envs/common.py

common/djangoapps/cache_toolbox/core.py

common/djangoapps/contentserver/middleware.py

common/djangoapps/user_api/middleware.py

common/djangoapps/xmodule_django/models.py

common/lib/xmodule/xmodule/contentstore/content.py

common/lib/xmodule/xmodule/contentstore/mongo.py

common/lib/xmodule/xmodule/modulestore/__init__.py

common/lib/xmodule/xmodule/modulestore/mixed.py