Merge pull request #240 from matrix-org/refresh

synapse/api/auth.py

synapse/handlers/auth.py

synapse/handlers/register.py

synapse/rest/client/v1/login.py

synapse/rest/client/v2_alpha/__init__.py

synapse/rest/client/v2_alpha/tokenrefresh.py

synapse/storage/__init__.py

synapse/storage/_base.py

synapse/storage/registration.py

synapse/storage/schema/delta/23/refresh_tokens.sql

tests/api/test_auth.py

tests/handlers/test_auth.py

tests/rest/client/v1/test_presence.py

tests/rest/client/v1/test_rooms.py

tests/rest/client/v1/test_typing.py

tests/rest/client/v1/utils.py

tests/rest/client/v2_alpha/__init__.py

tests/storage/test_registration.py

tests/utils.py