Started refactoring

Implemented a standalone switch exerciser demo. ...

Note this only really works with Adaptor Plus
(unless you seed the directory with your device id's first)

Started work on OOK support. ...

Ported C code into radio.py
Split out monitor and switch. Monitor.py is now just a monitor.
Switch.py needs more work to make it just a switch.
legacy.py will be a demo app for legacy (green button) devices.