Changed behavior of RNH_power and it's coresponding RCI command

RNH_power will now return state of selected pins in RNH_POWER_ON
and RNH_POWER_OFF.

The RCI commands #FF_P and #ON_P have been condensed to #PORT whose
first byte argument is an action and second byte is a bitmask of ports
to take that action on. The valid actions are:
0: STATUS
1: FAULT
2: ON
3: OFF
Merge branch 'master' of github.com:psas/stm32