A 'go for broke' OOK transmitter added to hrf69_test

Implemented most of hrf69.c write and read functions

HRF_write_reg written

Factored out all stdio from all testers and code

Mock read and write test working for radio register

Proved that we can read a register back from simulation

First pass at writing a test in hrf69_test.c

Marked the interface queries in HRF69.h

First attempt at specing out implementation of HRF69 based on python

spi_test working on Mac

Refactored delay into a platform module

gpio_sim working on Mac

Wrote GPIO simulator in a mostly platform independent way.

Framework in place for Arduino GPIO and simulated GPIO

GPIO is now tagged as RPi specific in build process

Created file architecture for arduino build

Started refactoring

Moved all C into a drv folder.

First pass at defining hrf69.h and radio.h interfaces

Started to refactor code into C

Pre-factoring work done prior to pushing more code into the C domain.

Tweaked payload format further. ...

Reset all devices and re-learnt the house code
Can now switch all devices on and off, together, and independently.
legacy.py test code now demonstrates this in a loop

Added a test mode to test all 16 patterns of legacy control messages. ...

Run legacy.py and try numbers 0 to F in learning mode.
In theory you should be able to select 4 different switch addresses
plus an 'all addresses', but I can't get this to work on my 7 plugs,
they all respond as switch number 1 regardless of what code I send
in learning mode.

Attempts to get multiple device addresses working. ...

Seems to be a discrepancy between documentation and sample C code.
Stopping here until I get this clarified.

Renamed modulator as encoder

7 legacy adaptors now turning on and off with this trimmed code

Improved reliability of syncing of OOK messages

Got old code working again. ...

Looks like the extra bytes inserted by the buffer bug actually make it work.
This is probably related to sync bytes

Merge branch 'master' of https://github.com/whaleygeek/pyenergenie

Brought back old test code that was working