Propagate preventDefault() to original event

This is related to #4. If I have a custom event handler for `tap`, `doubletap`, `flick`, `drag`, etc. that calls `event.preventDefault()`, then Finger should call `event.preventDefault()` on the **original** event that triggered `stopHandler()`.

This allows you to prevent the default behavior (native clicks, text selection, etc.) but *only* in cases where a Finger event was triggered and the default action was prevented.

Something like this seems to do the job:

	var fakeEvent = $.Event(evtName, data.move);
	$.event.trigger(fakeEvent, null, event.target);
	if(fakeEvent.isDefaultPrevented()) {
		event.preventDefault();
	}

Since this would only apply in cases where a custom event handler calls `event.preventDefault()`, I don't think this even needs an option in Finger (obviously, just don't call `event.preventDefault()` if you want the default behavior of the browser).