Conflicts:
	synapse/rest/client/v1/login.py

This allows refresh tokens to be exchanged for (access_token,
refresh_token).

It also starts issuing them on login, though no clients currently
interpret them.

Clean up some of restructured text formatting in the README.rst

Add generic update instructions to UPGRADE.rst

Add m.room.avatar to default power levels.

We're about to have two kinds of token, access and refresh

Fix set password

Add m.room.avatar to default power levels. Change default required power levels of such events to 50

I prefer the auth handler to worry about all auth, and register to call
into it as needed, than to smatter auth logic between the two.

Push: store the 'last_token' in the db, even if we processed no events

Always return a thumbnail of the requested size.

Add server side support for canonical aliases

Support logging in with email addresses (or other threepids)

Changes for unique emails

Don't get apservice interested rooms in RoomHandler.get_joined_rooms_for_users

I made the non-test seconds instead of ms, but not the test