Started to plan out the tx/rx pipeline for payloads and message buffers

Initial design of a message Router

Capabilities of devices turned into flags, with query method in base class

Mock registry store created, auto_create is working

Started to implement device classes code. ...

Simple mocking interface now working.

Method signatures for Registry sketched out

Python 3 now supported. ...

Logger now stores apparent power and real power headings.
Logger now stores temperature from eTRV in csv file

Tested FSK tx and rx on Pi, works fine ...

Tested both monitor.py and switch.py

Refactored so that we can create a tx-only switch loop tester. ...

This will be useful for integrating a new FSK transmitter without receiver