Added support for the MinIMU-9 v3 and bumped the version to 2.0.0.
calibrator: Changed it to use scipy for optimization.
More improvements for minimu9-ahrs-calibrator:
* Print a warning if there are fewer than 300 input vectors instead of exiting.
* Print a warning if the calibration looks wrong.
LSM303: Fixed a problem in readMag introduced in a recent commit.