This PR LGTM as it addresses my main need, although I think it'd be better to add support for the rest of options from RFC 2132 (eventually).
When talking about request as an option I'm talking about adding a way to add a request (or also request) statement to dhclient.conf. I need to requst subnet-mask, routers, rfc3442-classless-static-routes from my ISP, and the current implementation doesn't allow me to do that.