Merge pull request #1635 from matrix-org/erikj/split_out_fed_txn

jenkins-dendron-postgres.sh

synapse/app/federation_sender.py

synapse/config/server.py

synapse/federation/__init__.py

synapse/federation/federation_client.py

synapse/federation/replication.py

synapse/federation/send_queue.py

synapse/federation/transaction_queue.py

synapse/handlers/__init__.py

synapse/handlers/devicemessage.py

synapse/handlers/federation.py

synapse/handlers/initial_sync.py

synapse/handlers/message.py

synapse/handlers/presence.py

synapse/handlers/receipts.py

synapse/handlers/typing.py

synapse/notifier.py

synapse/replication/expire_cache.py

synapse/replication/resource.py

synapse/replication/slave/storage/_base.py