Add a gesture service for easier touch gestures

Wrote this for use with my mobile stuff and to make swipe gestures easier. Ported over the single swipe used in side drawer, will use it more in the other mobile changes.

Currently handles only swipe gestures, direction, threshold and tolerance for differing directions are all in arguments.

The interface may not be the cleanest, as it requires the parent component to handle constructing, touch begin and touch update, but it was very simple to do it this way.