MS_unwind_pm_90
MS_UNWIND_PM_90 - Unwind an angle until it is between 0 and 360 degrees
Utility function to find the equivelent angle between 0 and 360 degrees.
[angle] = unwind_pm_90(angle_in)
Usage: for a given value of angle_in return a value greater than -90 and less than or equal to 900 by repetedly adding or subtracting 180. Angle can be a scalar or a vector.