hoisie/web — pull request #158 by Archs (2013-09-06 15:18:01+00:00)
Title: Reset Content-Type when doing route.httpHandler

`http.ServeFile` tries to set file content type only if the `Content-Type` has not been set before.
If web.go does the setting in `web.Handler` funcs, web.go would not be able to work fine with the other `net/http` based packages.