Added reverse ato functionality to swap the behavior for each switch

ReefAngel.ReverseATOLow()
ReefAngel.ReverseATOHigh()

to reverse the behavior of each switch.

These are the updates to feature.txt as that is not in the repository.

ATO_LOW_REVERSE,ReefAngel.ReverseATOLow,Reverse ATO Low
ATO_HIGH_REVERSE,ReefAngel.ReverseATOHigh,Reverse ATO High