ocaml-topkg first version

[Hendrik Tews <hendrik@askra.de>]

Hi,

I uploaded a first version of topkg into the git repo. I decided
to only do the development package libtopkg-ocaml-dev, because
the main use of topkg is from a pkg/pkg.ml file starting with

    #use "topfind"
    #require "topkg"
    open Topkg

and this requires the cmi file. For the same reason I depend on
libfindlib-ocaml-dev, although one could argue that
libfindlib-ocaml-dev should be recommends.

Bye,

Hendrik