Mysensors

Like communicated per email, MySensors support.

Things are as far as I can see reasonably working although I tested only the serial gateway and one sensor up-till-now.

I did chose to use devicetype 3000 for MySensors as it might be that just like for KNX a DomotiGa devicetype for each MySensors ValueType (see http://www.mysensors.org/build/serial_api) might be appropriate.