New upstream version 0.9.1.
- Remove all patches; they have been upstreamed.
- Change source URL to include the package name.
- BR ocaml-lwt-ppx-devel instead of ocaml-lwt-devel.
- Invoke ocamlmklib with -g and $RPM_LD_FLAGS.
- BR ocaml-ocamldoc and build documentation.