Merge remote-tracking branch 'origin/develop' into dbkr/email_notifs

docs/log_contexts.rst

synapse/api/auth.py

synapse/federation/federation_server.py

synapse/federation/transaction_queue.py

synapse/federation/transport/server.py

synapse/handlers/_base.py

synapse/handlers/federation.py

synapse/handlers/presence.py

synapse/replication/resource.py

synapse/rest/__init__.py

synapse/rest/client/v2_alpha/openid.py

synapse/rest/client/v2_alpha/report_event.py

synapse/storage/__init__.py

synapse/storage/events.py

synapse/storage/openid.py

synapse/storage/prepare_database.py

synapse/storage/registration.py

synapse/storage/room.py

synapse/storage/roommember.py

synapse/storage/schema/delta/32/openid.sql