Fix to remove partially watched videos from result of queryset.
Merge pull request #2768 from mrpau/hotfix/2271-Export-CSV-data-quality-issues

Fix to remove partially watched videos from result of queryset.
Make default uuid generation random (uuid4), not based on counter.
Make counter incrementing more atomic, to avoid race conditions.
Move the old version of get_uuid into the new method, for reference.
Merge pull request #2818 from jamalex/fix_uuid_race_conditions

Fix UUID race conditions
decrease query test # of expected queries threshold, because we're
needing less queries now to compute the uuid
metadata for v0.12.10
corrected metadata for v0.12.10
Merge pull request #2820 from learningequality/release-0.12.0

Release 0.12.10