Merge branch 'develop' of github.com:matrix-org/synapse into erikj/state_ids_api

jenkins-dendron-postgres.sh

jenkins-postgres.sh

jenkins-sqlite.sh

jenkins/clone.sh

scripts/synapse_port_db

synapse/federation/federation_server.py

synapse/federation/transport/server.py

synapse/handlers/device.py

synapse/handlers/e2e_keys.py

synapse/rest/client/v2_alpha/keys.py

synapse/server.py

synapse/server.pyi

synapse/storage/end_to_end_keys.py

synapse/storage/events.py

synapse/storage/schema/delta/33/devices_for_e2e_keys.sql

...ma/delta/33/devices_for_e2e_keys_clear_unknown_device.sql

tests/handlers/test_e2e_keys.py

tests/storage/test_end_to_end_keys.py