Halohome

- Sort devices by RSSI before connecting to avoid unnecessary delay

(BREAKING)

- Remove support for `user_id` (username/email is sufficient)
- Support offline loading of devices (e.g. in case of internet outage)

- Read `user_id` to provide a permanent ID for the HALO Home account

- Raise HaloHomeError when credentials are not valid

- Support mesh communication (only need to connect to a single device
to control all of them)
- Make network and bluetooth connections async

- Initial release