Merge pull request #530 from matrix-org/erikj/server_refactor

synapse/app/homeserver.py

synapse/federation/__init__.py

synapse/federation/replication.py

synapse/federation/transport/__init__.py

synapse/federation/transport/client.py

synapse/federation/transport/server.py

synapse/server.py

tests/federation/__init__.py

tests/federation/test_federation.py

tests/rest/client/v1/test_presence.py

tests/test_types.py

tests/utils.py