Merge branch 'develop' of github.com:matrix-org/synapse into release-v0.18.2

synapse/api/auth.py

synapse/api/ratelimiting.py

synapse/app/homeserver.py

synapse/appservice/__init__.py

synapse/config/appservice.py

synapse/handlers/_base.py

synapse/handlers/auth.py

synapse/handlers/message.py

synapse/handlers/room.py

synapse/handlers/typing.py

synapse/metrics/__init__.py

synapse/metrics/metric.py

synapse/metrics/process_collector.py

synapse/push/emailpusher.py

synapse/push/mailer.py

synapse/rest/client/v2_alpha/filter.py

synapse/storage/_base.py

synapse/storage/schema/delta/37/user_threepids.sql

synapse/storage/stream.py

synapse/streams/events.py