Merge branch 'mj/registrace' into 'devel'

bin/create-user

bin/reset-user

db/db.ddl

db/upgrade-20210712.sql

db/upgrade-20210819.sql

etc/config.py.example

mo/__init__.py

mo/db.py

mo/email.py

mo/imports.py

mo/rights.py

mo/score.py

mo/tokens.py

mo/users.py

mo/util.py

mo/util_format.py

mo/web/__init__.py

mo/web/acct.py

mo/web/api.py

mo/web/auth.py