Shared flightbatterysettings:Renamed SensorCalibrations and created new field

SensorCalibrations was renamed to SensorCalibrationFactor
Created SensorCalibrationOffSet field. A new field was created because
it uses different units than SensorCalibrationFactor.
Battery Module:Use offset fields and scale factor to use mU.

The factor units were recently changed to use mV/V and mV/A but they
weren't properly scaled on the module.
UAVOMavlinkBridge:Use renamed SensorCalibration fields.
GCS Battery:Implement offset fields, allow higher than "1" val on factor fields.
Merge pull request #5 from guilhermito/#1037

Implements sensor offset and fixes factor scaling.