Also include the compiler standard libraries under compiler-libs/, as this
is the convention adopted by other packaging (Debian, FreeBSD), and is used
by various utility software such as the Lwt interactive toplevel and some
of the graphical IDEs.
Also modify ocaml.port.mk to depend on the exact version of ocaml being
compiled against, since the OCaml library format makes no guarantees about
working across versions. This dependency should ensure that packages compiled
against different ocaml versions aren't mixed and matched.