Merge branch 'mj/contest-reform' into 'devel'

db/db.ddl

db/upgrade-20210924.sql

etc/config.py.example

mo/__init__.py

mo/db.py

mo/imports.py

mo/jobs/submit.py

mo/rights.py

mo/web/acct.py

mo/web/jinja.py

mo/web/org.py

mo/web/org_contest.py

mo/web/org_place.py

mo/web/org_round.py

mo/web/org_score.py

mo/web/org_users.py

mo/web/table.py

mo/web/templates/org_contest.html

mo/web/templates/org_contest_add_user.html

mo/web/templates/org_contest_advance.html