Merge pull request #51 from qiniu/develop

inc version number
Merge pull request #54 from qiniu/develop

Release v2.4.3
Merge pull request #58 from qiniu/develop

merge develop to master
Merge pull request #63 from qiniu/develop

merge to master
Merge pull request #66 from qiniu/develop

correct NodeJS to Node.js
Merge pull request #72 from qiniu/develop

Release 6.0.0
fix "global leak detected: i"; use blanket instead of jscoverage
use urllib instead of http(s)
add default rpc timeout: one hour
Merge pull request #75 from fengmk2/urllib

Using urllib fixed #74