Merge pull request qiniu#354 from liangchaoboy/master

add version

fix useless code

update changelog of v7.2.11

update changelog to publish v7.2.10

fix code style for static variables in Configuration

Merge pull request qiniu#308 from jemygraw/master

add new putpolicy parameter and update changelog

Merge pull request qiniu#265 from jemygraw/master

7.2.4;changelog;update version

Merge pull request qiniu#251 from sxci/7.2.3

7.2.3; changelog; autozonebuckettest

Merge pull request qiniu#238 from longbai/upload_stream

add stream upload

Merge pull request qiniu#235 from longbai/fixed_pili_streaming_expire

fixed streaming expired