Fix delete cache so it also deletes location with run = None.
Merge pull request #3668 from edx/opaque-keys-fix-cache-content-diff-runs

Fix delete cache so it also deletes location with run = None.
Fix discussions by correctly serializing outgoing course_ids
Fixing ORA
Merge pull request #3674 from edx/flowerhack/fix-ora

Flowerhack/fix ora
fixup! Fix discussions by correctly serializing outgoing course_ids
Merge pull request #3669 from cpennington/opaque-keys-fix-discussion-tests

Fix discussions by correctly serializing outgoing course_ids
Migration refactoring
Let sql tell us if the data is unique
fixup! Migration refactoring
Merge pull request #3675 from edx/opaque-keys-migrate

Opaque keys migrate
Fix @feanil Traceback from Logs(TypeError: 'SlashSeparatedCourseKey' object is not iterable)
Pass deprecated course keys through
Make Locators comply with UsageKey accessors
Merge pull request #3687 from edx/flowerhack/fix-discussion-opaque

Flowerhack/fix discussion opaque
fix staff_grading server error
Merge pull request #3530 from edx/dhm/opaque-locator

Make Locators comply with UsageKey accessors
Merge pull request #3688 from edx/dhm/opaque-keys-bugs

Dhm/opaque keys bugs
Merge remote-tracking branch 'edx/opaque-keys' into opaque-keys-merge-master