Merge pull request #2054 from matrix-org/erikj/user_iter_cursor

synapse/replication/slave/storage/events.py

synapse/storage/_base.py

synapse/storage/account_data.py

synapse/storage/deviceinbox.py

synapse/storage/devices.py

synapse/storage/end_to_end_keys.py

synapse/storage/event_federation.py

synapse/storage/event_push_actions.py

synapse/storage/events.py

synapse/storage/prepare_database.py

synapse/storage/receipts.py

synapse/storage/registration.py

synapse/storage/room.py

synapse/storage/roommember.py

synapse/storage/signatures.py

synapse/storage/state.py

synapse/storage/tags.py

tests/storage/test_base.py