Adds ocaml-gtktop

Gtktop is a small OCaml library to ease the creation of graphical
toplevels.

Homepage: http://zoggy.github.io/gtktop/

pkgs/development/ocaml-modules/gtktop/default.nix

@@ -0,0 +1,25 @@
+{ stdenv, fetchurl, ocaml, camlp4, findlib, lablgtk-extras }:
+
+let pname = "gtktop-2.0"; in
+
+stdenv.mkDerivation {
+  name = "ocaml-${pname}";
+
+  src = fetchurl {
+    url = "http://zoggy.github.io/gtktop/${pname}.tar.gz";
+    sha256 = "0cpmnavvham9mwxknm6df90g9qxabcvn2kfwlf9mncqa0z3rknz6";
+  };
+
+  buildInputs = [ ocaml camlp4 findlib ];
+  propagatedBuildInputs = [ lablgtk-extras ];
+
+  createFindlibDestdir = true;
+
+  meta = {
+    homepage = http://zoggy.github.io/gtktop/;
+    description = "A small OCaml library to ease the creation of graphical toplevels";
+    license = stdenv.lib.licenses.lgpl3;
+    maintainers = with stdenv.lib.maintainers; [ vbgl ];
+    platforms = ocaml.meta.platforms;
+  };
+}

pkgs/top-level/all-packages.nix

@@ -3747,6 +3747,8 @@ let
 
     gmetadom = callPackage ../development/ocaml-modules/gmetadom { };
 
+    gtktop = callPackage ../development/ocaml-modules/gtktop { };
+
     js_of_ocaml = callPackage ../development/tools/ocaml/js_of_ocaml { };
 
     lablgl = callPackage ../development/ocaml-modules/lablgl { };