Update opaque_keys docs

Update get_discussion_link command to use CourseKeys

Ensure all cms commands accept either deprecated or new syntax for keys

LMS-2712

Merge master into opaque-keys

Dhm/opaque no asset

Conflicts:
	common/lib/xmodule/xmodule/video_module/video_handlers.py

Fix bug affecting video transcripts in XMLModulesStore courses

Add mime-type for srt and sjson when importing course. 

Ahodges/documentation/doc156

Conflicts:
	lms/djangoapps/courseware/tests/test_views.py
	lms/djangoapps/instructor/tests/test_api.py
	lms/djangoapps/instructor/tests/test_legacy_anon_csv.py
	lms/djangoapps/instructor/views/api.py
	lms/djangoapps/instructor/views/legacy.py

Changing Student Anon ID Dump to return Course Specific IDs.

Changes for LMS-2591, Instructor Dash switchover

DOC-405: privileges in Studio=privileges in LMS

Rebalance CMS acceptance test shards

Fix improper parsing of location string

Ahodges/documenttion/doc387

Adam/fix non ascii grade range

May change log fix

More missing ORA fixes.

Text changed in admin_dashboard for course enrollments.