TradHeli: Simplification of the method used to control Ext. Gyro gain with Ch6 Tuning.  This is not perfect, as we are not actually checking if Ext. Gyro is active, so this could in fact be also used to control the other Heli Ch7 functions (direct drive tail rotor control).  This should be tidied up.

Credit: Jolyon Saunders
TradHeli: Integrating Cross-Coupling Compensation.  This corrects off-axis disk tilt which occurs during rapid swash plate angle changes on helis.

Credit: Jolyon Saunders