change main loop to mostly use voltish instead of volts
adjust doKnob() for 50K knob wired on two-conductor cable to 50K resistor
deleted unused code, improved printout routines, fixed some indentation
make doLeds() look at voltish not volts (IMPORTANT), look at presentLevel instead of comparing voltages
make turnThemOffOneAtATime() correctly address ledPins[] (IMPORTANT)
make turnThemOffOneAtATime() fully correctly address ledPins[] (IMPORTANT)
finish serial data reception in readSerial()