Add gyro smoothing threshold

[JustinWayland]

This is the best way to compensate for slightly shaky hands when using gyro.

In essence, below a certain turning threshold the gyro values are "smoothed" to help players with shaky hands only turn when they intend to, while above that threshold gyro values basically enter the system as is to ensure the gyro feels responsive.

Woof! has a working example of this to try to adapt.