SwipeLayout: Allow childs to deny swipe gesture

When used with ScorllView(or horizontal) inside SwipeLayout, the swipe
gesture may conflict with the scroll action. If use requestDisallowInterceptTouchEvent, the scroll action will be back but the parent ListView's scroll action may be disallowed too.

This patch solved this problem by introducing a "SwipeDenier"
interface whose implementation should return if this swipe event should
be denied. When onInterceptTouchEvent is called, SwipeLayout will call
all SwipeDenier and if one of them returns true, the event will not be
intercepted and passed to child views.

Tested in app: https://github.com/PaperAirplane-Dev-Team/BlackLight
which requires HorizontalScrollView inside SwipeLayout

Signed-off-by: Peter Cai <xqsx43cxy@126.com>
Merge pull request #7 from PeterCxy/patch-2

SwipeLayout: Allow childs to deny swipe gesture