* refactor: moves is_content_creator
from cms.djangoapps.contentstore.helpers to common.djangoapps.student.auth
* feat: adds content tagging app
Adds models and APIs to support tagging content objects (e.g. XBlocks,
content libraries) by content authors. Content tags can be thought of as
"name:value" fields, though underneath they are a bit more complicated.
* adds dependency on openedx-learning<=0.1.0
* adds tagging app to LMS and CMS
* adds content tagging models, api, rules, admin, and tests.
* content taxonomies and tags can be maintained per organization by
content creators for that organization.
8098169eca