Update to OCaml 4.02.1, opam 1.2.0, findlib 1.5.5*
Update to OCaml 4.02.1, opam 1.2.0, findlib 1.5.5*

'-r' does not install findlib before installing opam

* - ocamlbrew-installed findlib won't currently work with OCaml 4.02.1
because findlib requires camlp4 and OCaml 4.02.x doesn't include camlp4 in
the main distribution.  Installing findlib via opam should still work
properly.

hcarty/ocamlbrew