Merge branch 'release-v0.19.0' of github.com:matrix-org/synapse

CHANGES.rst

README.rst

docs/admin_api/purge_remote_media.rst

synapse/__init__.py

synapse/api/auth.py

synapse/app/appservice.py

synapse/app/client_reader.py

synapse/app/federation_reader.py

synapse/app/federation_sender.py

synapse/app/homeserver.py

synapse/app/media_repository.py

synapse/app/pusher.py

synapse/app/synchrotron.py

synapse/config/emailconfig.py

synapse/config/logger.py

synapse/config/server.py

synapse/config/voip.py

synapse/config/workers.py

synapse/event_auth.py

synapse/events/__init__.py