documents for two new features
Merge pull request #71 from cfsego/master

documents for two new features
update trim doc.
Merge pull request #72 from taoyuanyuan/master

update trim doc.
Update index.html
Update documentation.html
Update documentation_cn.html
update trim doc.
Merge pull request #73 from taoyuanyuan/master

update trim doc.
Update documentation_cn.html
improve the document of http_upstream_check_module
Merge pull request #75 from lilbedwin/doc_cn

improve the document of http_upstream_check_module
improve document, "HEAD" method is recommended in upstream check module
Merge pull request #76 from lilbedwin/doc_cn

improve document, "HEAD" method is recommended in upstream check module
update trim doc
Merge pull request #77 from taoyuanyuan/master

update trim doc
tengine 2.0.1
Merge commit 'alibaba/master' into update