FlyingDot: Simplified vector handling in setLocalFrame() method
FlyingDot: Initialize axisZs constants in static {} block
DataSlider: Removed color fields
DataSlider: Removed trivial init() method
GliderUser: Move VarioMeter.tick() call out of GliderUser.tick()

GliderUser shouldn't know about any variometer
GliderUser: Moved VarioMeter instance into XCGame class
GliderUser: Added missing @Override decorator