OP-975 fix message at end of calibration
OP-975 Split level/gyro calibrations, base level calibration on board rotation, a lot more refactoring/cleanup
OP-975 Move six points calibration to a reusable class
OP-975 Move board level calibration to a reusable class
OP-975 Move gyro zero bias calibration to a reusable class
OP-975 cleanup