Use of the power function to square a number can be very inefficient depending on processor and compiler. Replace with an inlined function that multiplies the number by itself. This has not been put into the maths library because the use of the sq() function is peculiar to the autocode generated for the EKF and an inlined function was desired.
Set conservative defaults as a baseline for tuning
Add a missing parameter for magnetometer observation noise.
Correct error in definition of magnetic heading observations noise (previous parameter defined the variance directly, not the noise).
Scale vertical GPS noise to allow for average EPV to EPH ratio.
Update documentation and display names for consistency.
