Merge pull request qiniu#131 from simon-liubin/update/remove-print

remove System.out.print

Merge pull request qiniu#128 from qiniu/develop

Release 6.1.6

Merge pull request qiniu#121 from qiniu/develop

Release 6.1.5

Merge pull request qiniu#115 from qiniu/develop

Release 6.1.4

Merge pull request qiniu#109 from qiniu/develop

Release 6.1.3

Merge pull request qiniu#98 from qiniu/develop

Release v6.1.2

Merge pull request qiniu#93 from qiniu/develop

merge develop to master

Merge pull request qiniu#64 from qiniu/develop

Releaes v6.0.0

PutPolicy add asyncOps

http client connpool (continue)