changed code to work as in adafruit example, using reference resistor
changed level sensor pin to match main2
changed liquid level sensor pin to regular digital pin, from comms pin
COMPILES; defined LED pin, added frtizing
replaced liquid level code in main with code that uses reference resistor; updated variable names; removed some code pertaining to float switches
COMPILES; added back tank setpoints (were deleted accidentally)
remove frtizing files because git cannot merge them
COMPILES; merged branch addRefResistorLevelSensor into mergeLevelCode