Sync documentation of English with Chinese version
Merge pull request #93 from Unknwon/master

Sync documentation of English with Chinese version.
fix setcookie time type
fix #91
Fixed bug: error page cannot show correct corresponding status code
Merge pull request #98 from Unknwon/master

Fixed bug: error page cannot show correct corresponding status code
add validators
add validation funcs
add test
Merge pull request #100 from miraclesu/valid

Valid
Merge pull request #2 from astaxie/master

merge