Added roomName, a directive to compute a room name based on its alias (not aliases for now) and its users displaynames or ids

Little bit more on syncing APIs, need to know more about responses before more work can be done on it.

Fairly simple move of the call status widget to the header bar (and therefore into the index page rather than the rooms page).

Have MemoryDataStore's get_rooms_for_user_where_membership_is() return room membership event objects, as per interface contract

Handle call events in the recents view as well to get consistency with what it displays when refreshed.

Just show 'Call' for call events. Don't just splat out the content of the event for other events: it's rarely going to be sesnible.

Rename 'state' presence key to the much more obvious 'presence'; maintain a legacy 'state' copy for now

Fleshed out joining/leaving rooms. Added M_LIMIT_EXCEEDED standard error code for rate limited requests.

Added /web folder which contains html/css (based off the default swagger-ui) for viewing the c-s json api.

BF: Pass desired_user_id to register API. And update the app header to avoid to display the previous matrix id