beego: fix the Upper for the _method value
Update beego.go
fix not found when has mulit static dir

 robot &robots
fix the static file dir
fix the same name controller for UrlFor
Merge pull request #826 from SnailKnows/patch-2

Update beego.go
beego: flash add success & Set
update the isdir
Merge remote-tracking branch 'upstream/develop'