Add interfaces to be in sync with Python

[mkrebs81]

After v2.0.0 has been released, add interfaces to device API. This will match the Python interfaces more closely.

Generic Device API

• connectAsync()
• disconnectAsync()
• getValueAsync()
• setValueAsync(FP, DP)
• [x] canSubscribe()
• [x] subscribe(FP, DP)
• [x] unsubscribe(FP, DP)
• [x] getValues (device, FP, DP)

Note: authenticate() method will be called from within connect(Async) and not exposed to generic API.

[mkrebs81]

also add generic setVal with dynamic properties, as defined in REST.

ignore the properties when the interface does not support them.

[mkrebs81]

not implementing the async methods, because async execution requires external process and cannot be encapsulated yet.