Merge pull request #16 from yeol/master

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Draft
resolve conflict
Merge pull request #17 from yeol/master

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添加jpeg头部信息解析，和压缩保留头部信息功能
直接使用plupload中的server代码
添加chunk传输支持
Merge pull request #18 from liaoxuezhi/master

提交代码
添加orientation自动调整
Merge pull request #19 from liaoxuezhi/master

添加orientation自动调整
dnd