Merge branch 'develop' into markjh/v2_sync_receipts

synapse/api/filtering.py

synapse/handlers/message.py

synapse/handlers/private_user_data.py

synapse/handlers/sync.py

synapse/notifier.py

synapse/rest/client/v2_alpha/__init__.py

synapse/rest/client/v2_alpha/sync.py

synapse/rest/client/v2_alpha/tags.py

synapse/storage/__init__.py

synapse/storage/schema/delta/25/tags.sql

synapse/storage/tags.py

synapse/streams/events.py

synapse/types.py

tests/rest/client/v1/test_presence.py