Replace swipeThreshold updates with the one in FlxTouchManager
Temporarily remove swipeThreshold sets for testing.
Proper SwipeUtil refactoring. Completely replaced all flick and movement checks with the one in Flixel. Rewrote most of the documentation to be more accurate.
Invert flick checks as it already comes inverted from FlxFlick.
Define fixes for SwipeUtil
Fixed null safety issues on compiling.