CUAV CAN PMU Autopilot Power Module

Analog voltage/current sensing works fine on its own, but it sits oddly on a flight stack where every other peripheral reports over CAN - mixing an analog power module into an otherwise-digital bus adds a point of inconsistency. CUAV's CAN PMU reports power data the same way the rest of a CAN-standardized stack communicates, keeping the whole power-monitoring chain consistent with a build that's already committed to CAN for its other peripherals.