Bug fix for incorrect compressing

A band of low data was getting scrambled by a simple test optimisation
mistake.
Re-calibrated lux levels for SMD sensor in case
Debug output for phase data sync state
Data sync searches last log for real data overlap!

Previous data sync is now used to search new data for a real data
overlap (data scent) and not just a time step estimate. Data sample
times are scaled to fit to match the system time logs for a much more
accurate data set and no clipping/repeats.
New BLE SMT board (version 0.7 revision A)

New hardware required some changes to micro-controller pin outs so will
require updated and different firmware branch.