Added option to bind events to container instead of wrapper.

I needed an option to attach the touch/click events to the container element instead of the wrapper. I think it might be userful for others too, so I decided to commit it. The reason I need this is sometimes you can have DOM elements other than the wrapper inside the container. For example I use buttons for swiping to the next and the previous element that are placed over the wrapper with absolute positiononing and z-index. But I also want to user dragging as a method of swiping. If the click/touch events are bound to the wrapper, then they don't fire if I try to swipe over the button. That's why I need to bind my events to the container.