一个支持Gif图片以及普通图片预览，支持双击缩放，单机退出，同时可以选择使用jni的形式去高效加载gif或者更更精简的(仅2个类)gif控件
详细介绍请查看博客：http://www.kymjs.com/code/2015/10/18/01/
##开源协议
Copyright (C) 2015, 张涛
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.