Add recursive function to check parent nodes up to normalScrollElementTo...

This is to attempt to fix the problem of allowing `normalScrollElements` to work on touch devices. Before it calls `event.preventDefault()` in `touchMoveHandler(event)`, it tests to see if the target element has one of the `normalScrollElements` in its parent nodes recursively and uses a new option, `normalScrollElementTouchThreshold` to limit the recursion.

additional: based on v2.0 - removed whitespace changes