Support for Humidifier/Dehumidifier

[webOSpinn]

Is your feature request related to a problem? Please describe:
My system has a built-in humidifier and it also uses the air conditioner to dehumidify.

Describe the solution you'd like:
It would be nice to expose the state, humidity target, water pad life of the humidifier. It would also be nice to expose the state and humidity target for the dehumidifier.

These appear to be the characteristics that apply:

• HMCharacteristicTypeCurrentRelativeHumidity - The current relative humidity measured by the accessory.
• HMCharacteristicTypeTargetRelativeHumidity - The target relative humidity for the accessory to achieve.
• HMCharacteristicTypeCurrentHumidifierDehumidifierState - The current state of a humidifier or dehumidifier accessory.
• HMCharacteristicTypeTargetHumidifierDehumidifierState - The state that a humidifier or dehumidifier accessory should try to achieve.
• HMCharacteristicTypeHumidifierThreshold - The humidity below which a humidifier should begin to work.
• HMCharacteristicTypeDehumidifierThreshold - The humidity above which a dehumidifier should begin to work.

For the humidifier pad it might make sense to use the filter characteristics:

• HMCharacteristicTypeFilterLifeLevel - The amount of useful life remaining in a filter.
• HMCharacteristicTypeFilterChangeIndication - A filter’s change indicator.
• HMCharacteristicTypeFilterResetChangeIndication - A reset control for a filter change notification.

Describe alternatives you've considered:
N/A

Additional context:
N/A