glsurf: use current giflib

This requires bumping the version of camlimages used by glsurf to a
version that supports current giflib.  The most recent versions of
camlimages (even of 4.x) don't support ocaml 4.01 any more, so I've
upgraded to 4.1.2 here, the last version that supports ocaml 4.01 (and
which happily supports current giflib).

pkgs/development/ocaml-modules/camlimages/4.0.nix

@@ -1,41 +0,0 @@
-{ lib, stdenv, fetchurl, omake, ocaml, libtiff, libjpeg, libpng, giflib, findlib, libXpm, freetype, graphicsmagick, ghostscript }:
-
-let
-  pname = "camlimages";
-  version = "4.0.1";
-in
-
-stdenv.mkDerivation {
-  name = "${pname}-${version}";
-
-  src = fetchurl {
-    url = "https://bitbucket.org/camlspotter/camlimages/get/v4.0.1.tar.gz";
-    sha256 = "b40237c1505487049799a7af296eb3996b3fa08eab94415546f46d61355747c4";
-  };
-
-  buildInputs = [ ocaml omake findlib graphicsmagick ghostscript ];
-
-  propagatedBuildInputs = [libtiff libjpeg libpng giflib freetype libXpm ];
-
-  createFindlibDestdir = true;
-
-  preConfigure = ''
-    rm ./configure
-  '';
-
-  buildPhase = ''
-    omake
-  '';
-
-  installPhase = ''
-    omake install
-  '';
-
-  meta = with lib; {
-    branch = "4.0";
-    homepage = "https://bitbucket.org/camlspotter/camlimages";
-    description = "OCaml image processing library";
-    license = licenses.lgpl2;
-    maintainers = [ maintainers.vbgl ];
-  };
-}

pkgs/development/ocaml-modules/camlimages/4.1.2.nix

@@ -0,0 +1,37 @@
+{ lib, stdenv, fetchFromGitLab, fetchpatch, omake, ocaml, findlib
+, graphicsmagick, ghostscript
+, freetype, giflib, libjpeg, libpng, libtiff, libXpm
+}:
+
+stdenv.mkDerivation rec {
+  pname = "camlimages";
+  version = "4.1.2";
+
+  src = fetchFromGitLab {
+    owner = "camlspotter";
+    repo = "camlimages";
+    rev = "98661d507e12ce91a51295a50f244cb8265b4439"; # no tag
+    sha256 = "0kpxj8wm2m17wjq217jzjpfgv1d7sp4w1yd1gi8ipn5rj4sid2j8";
+  };
+
+  buildInputs = [ ocaml omake findlib graphicsmagick ghostscript ];
+  propagatedBuildInputs = [ libtiff libjpeg libpng giflib freetype libXpm ];
+
+  createFindlibDestdir = true;
+
+  buildPhase = ''
+    omake
+  '';
+
+  installPhase = ''
+    omake install
+  '';
+
+  meta = with lib; {
+    branch = "4.0";
+    homepage = "https://bitbucket.org/camlspotter/camlimages";
+    description = "OCaml image processing library";
+    license = licenses.lgpl2;
+    maintainers = [ maintainers.vbgl ];
+  };
+}