Merge branch 'release-v0.6.0'

.gitignore

CHANGES.rst

README.rst

UPGRADE.rst

VERSION

docs/code_style.rst

docs/media_repository.rst

graph/graph2.py

scripts/check_event_hash.py

scripts/federation_client.py

scripts/upgrade_db_to_v0.6.0.py

setup.py

synapse/__init__.py

synapse/api/auth.py

synapse/api/constants.py

synapse/api/errors.py

synapse/api/events/__init__.py

synapse/api/events/room.py

synapse/api/events/validator.py

synapse/api/urls.py