Add a template file server module

This will be nice to add templated documentation to controllers. Example:

  nest :tutorial, Tap::Controller do
    def dispatch(route)
      if route == nil || route.empty?
        route = "index"
      end

      if path = module_path("#{route}.erb")
        render :file => path
      else
        raise ServerError.new("404 Error: page not found #{route}", 404)
      end
    end
  end