Notwritten route pass to NotFound handler

    m.Get("/:page", func(p martini.Params, r render.Render) {
        if p["page"] == "im-exists" {
            r.HTML(200, "page", "all ok")
        }
        // else (another matched but not exists) - do nothing, pass me to NotFound
    }

it`s a version 2 of #229