* Added support for setting MQTT username and password
- Setting MQTT_USERNAME to None will disable username and password for mqtt
* Added config for Oregon wind and rain sensor.
- Note, the device_class 'weather' is not supported in
Home Assistant see: https://www.home-assistant.io/integrations/sensor/
* Oregon sensors use both channel and id so the instance
variable will now support either one of them or both.
* Home Assistant will only allow edit of discovered
sensors in GUI if they have a unique_id set.
* Identifiers in the 'device' seems to be use to group
sensors in one group in home assistant
* Manufacturer in the 'device' is required to create a
group of sensors in Home Assistant.
