Remove the RadioHead RH_ASK class to avoid conflict.

Both our Timers class and RadioHead's RH_ASK use the Timer1 atmega
interrupt and can't be compiled together.  For now just drop that class
until someone needs it...

Also add missing consts in Sensorino::onRadioMessage.
The radio driver must be malloc'd.  First working example.

The radio driver was being allocated on stack and since there's no
refcounting it was destroyed to soon and the code segfaulted.

Add a first Arduino test sketch which seems to work, demonstrating
functional RelayService.