http://jsfiddle.net/gh/get/extjs/4.2/icattlecoder/jsfiddle/tree/master/uptoken
http://jssdk-v2.demo.qiniu.io/
https://developer.qiniu.com/kodo/sdk/1283/javascript
https://developer.qiniu.com/kodo/manual/1208/upload-token
https://github.com/qiniu/js-sdk/tree/1.x#usage