Changes made for Pathfinder 5226 controllers.

A setup parameter was added to specify a Backgauge Overshoot Distance which was implemented in the older controller models and has now been implemented into the 5226. This distance is used during the automatic mode whenever the backgauge must move toward the rear of the machine to achieve its next target. The backgauge will overshoot its target by this amount, then approach the target while moving toward the front of the machine. This functionality removes all back-lash from the backgauge mechanism by always approaching a target from a consistent direction.