Merge the data bit detection and data byte assembly into the same loop

Original code loops through the analogue array m[] detecting data bits
and putting them into the bits[] array. It then loops through all the
bits[] creating the msg[] byte array. It then loops through the analogue
array m[] again calculating the signal strength.

Change this so that everything is done in one loop so we can go straight
from analogue samples to bytes, calculating the signal strength on the
fly.

Also use the results of the signal strength calculation to populate the
message records mm.signalLevel variable.