新增基于七牛API封装的类QiniuSDK,QiniuRSTransfer,QiniuRSSDK,QiniuImageViewSDK

Signed-off-by: lunnlew <lunnlew@gmail.com>
Update README.md
新增资源管理接口DEMO
新增DEMO示例
新增上传下载接口DEMO
修改下载上传接口DEMO说明
将URL生成函数从QiniuSDK移到QiniuRSTransferSDK
Update README.md
Merge pull request #1 from lunnlew/Develop

从Develop合并新文件