fix urlencode bug

- utf-8 encode wrong
   before: `测试 +.txt` -> `%E6%B5_%E8%AF_%20+.txt`
   now: `测试 +.txt` -> `%E6%B5%8B%E8%AF%95%20+.txt`
- add debug mode in config, default is false

feat 云处理、Rest API 使用新的签名方式

Update README.md

Merge pull request upyun#19 from upyun/sabakugaara-patch-1

fix issue18

Merge pull request upyun#16 from upyun/feature/v3

Feature/v3

Merge pull request upyun#15 from phy25/patch-1

Remove duplicate bucketName in usage request url

bump version to 2.2.0

modify README.md