fix tests due to update of `should.js`
fix `connect-mongo` version
Revert "fix `connect-mongo` version"

This reverts commit 9db51a53341b23565cdaa4494e2649faa91223ea.
fix compression version
Revert "fix compression version"

This reverts commit fb81538cbf6b48bd54e5e8cdde8247535cb75dc1.
change middleware's sequence
fix #352
filter invalid messages
用ejs-mate替代ejs-locals。解决windows下layout.html文件位置不对的问题。去掉不再依赖的模块