add flag DISABLE_LIBRARY_CREATION

add comma

use CourseCreatorRole to determine if user can create a library

add disable library creation feature flag

Conflicts:
	cms/djangoapps/contentstore/views/course.py

ENABLE_CONTENT_LIBRARIES flag

check for course creator role for library creation

Conflicts:
	cms/djangoapps/contentstore/views/course.py

add unit tests

make check of creation of library a true/false for forntend, add security in api call, clean tests

update tests

fix docstring of tests

fixed quality violation

fixed broken unit test and quality violations

Feedback changes and unit test to assert libraries are visible to non staff users too

fixed quality violation and feedback changes

Instead, use a class attribute to define test behavior. This allows for
easier addition of new mixins over time.

Randomized Content Block editor did not check Studio user's permissions

mattdrayer: Default to XBlock class if no unmixed class

Conflicts:
	cms/djangoapps/contentstore/tests/test_courseware_index.py

Indexing moved to celery task. Reorganised indexing to always allow for full course reindex. Indexing code no longer needs to be in common, because it is triggered by signal instead of being called.g

TNL-836

TNL-1185

Retriggering Jenkins