Improve nested swipers support and noSwiping logic. Added new demo for nested horizontal swipers.

I've improved Isaac Strack's noSwiping logic and it's now possible to have nested horizontal (I guess vertical too) swipers. There are two main changes:
- when you touch somewhere, the most nested swiper grabs this event, it was ambigous previously,
- noSwipingClass is checked by swiper only on it's own slides, wrapper and container. Previously it checked all nested slides, wrappers and containters which was faulty.

I've attached a new demo that shows this clearly. Play with this, then comment out current 2.1 version JS file and use development JS to see improvements.