Merge branch 'develop' into pushrules2

CHANGES.rst

UPGRADE.rst

scripts/upgrade_appservice_db.py

synapse/app/homeserver.py

synapse/appservice/__init__.py

synapse/config/ratelimiting.py

synapse/config/server.py

synapse/federation/federation_client.py

synapse/federation/federation_server.py

synapse/federation/transaction_queue.py

synapse/federation/transport/__init__.py

synapse/federation/transport/client.py

synapse/federation/transport/server.py

synapse/handlers/directory.py

synapse/handlers/events.py

synapse/handlers/federation.py

synapse/handlers/register.py

synapse/handlers/room.py

synapse/http/client.py

synapse/notifier.py