📦 Enable the RecyclerView to support loading more and customizing the footer view without modifying the original adapter of the RecyclerView. 在不改动 RecyclerView 原有的 adapter 的情况下，使 RecyclerView 滑动到底部的时候能够加载更多和自定义底部视图。
add function: setNotShowFooterWhenNotCoveredScreen #25
update canScroll(), fix canScrollVertically(-1) is always false
refactor: sync hasStableIds
feat: func setHasStableIds and setOnStableIdCallback
update gradle compileSdkVersion: 28 buildToolsVersion '28.0.3' targetSdkVersion 28 supportLibVersion = '28.0.0'
support show load failed view and can retry click to load more
make NoMoreHolder and FooterHolder public
add getFooterView() and getNoMoreView()
override public void onBindViewHolder(RecyclerView.ViewHolder holder, int position, List<Object> payloads)
auto load more when no data is initialized