Merge branch 'develop' into matthew/filter_members

changelog.d/3555.feature

changelog.d/3590.misc

changelog.d/3591.misc

docs/workers.rst

synapse/api/auth.py

synapse/app/client_reader.py

synapse/handlers/__init__.py

synapse/handlers/appservice.py

synapse/handlers/initial_sync.py

synapse/handlers/message.py

synapse/handlers/pagination.py

synapse/handlers/room.py

synapse/rest/client/v1/admin.py

synapse/rest/client/v1/room.py

synapse/server.py

synapse/storage/events.py

synapse/storage/pusher.py