Add OCaml Oasis

OCaml Oasis is a configure/build/install system for OCaml proget (like
Cabal for Haskell).

This commit also add a few small dependencies that where missing

  -  OCaml Data Notation (odn)
  -  ocamlify
  -  ocamlmod

pkgs/development/tools/ocaml/oasis/default.nix

@@ -0,0 +1,32 @@
+{stdenv, fetchurl, ocaml, findlib, ocaml_data_notation, ocaml_typeconv,
+ ocamlmod, ocamlify, ounit, expect}:
+
+stdenv.mkDerivation {
+  name = "ocaml-oasis-0.4.1";
+
+  src = fetchurl {
+    url = http://forge.ocamlcore.org/frs/download.php/1355/oasis-0.4.1.tar.gz;
+    sha256 = "1lsnw9f1jh6106kphxg40qp0sia6cbkbb9ahs5y6ifnfkmllkjhj";
+  };
+
+  createFindlibDestdir = true;
+
+  buildInputs =
+    [
+      ocaml findlib ocaml_data_notation ocaml_typeconv ocamlmod ocamlify ounit
+    ];
+
+  configurePhase = "ocaml setup.ml -configure --prefix $out";
+  buildPhase     = "ocaml setup.ml -build";
+  installPhase   = "ocaml setup.ml -install";
+
+  meta = {
+    homepage = http://oasis.forge.ocamlcore.org/;
+    description = "Configure, build and install system for OCaml projects";
+    license = stdenv.lib.licenses.lgpl21;
+    platforms = ocaml.meta.platforms;
+    maintainers = with stdenv.lib.maintainers; [
+      z77z
+    ];
+  };
+}