code: function norender(app, ext, file, locals) {
    return !app.engines.hasOwnProperty(ext)
      || app.isTrue('norender') || app.isFalse('render')
      || file.norender === true || file.render === false
      || locals.norender === true || locals.render === false;
  }
docs: Push the `file` through if the user has specfied
  not to render it.