gtkmm3: update 3.16.0 -> 3.18.0

Also remove urkud for maintainers; he's been inactive for years,
so let's not bother him anymore.

pkgs/development/libraries/gtkmm/3.x.nix

@@ -1,7 +1,7 @@
-{ stdenv, fetchurl, pkgconfig, gtk3, glibmm, cairomm, pangomm, atkmm }:
+{ stdenv, fetchurl, pkgconfig, gtk3, glibmm, cairomm, pangomm, atkmm, epoxy }:
 
 let
-  ver_maj = "3.16";
+  ver_maj = "3.18";
   ver_min = "0";
 in
 stdenv.mkDerivation rec {
@@ -9,17 +9,18 @@ stdenv.mkDerivation rec {
 
   src = fetchurl {
     url = "mirror://gnome/sources/gtkmm/${ver_maj}/${name}.tar.xz";
-    sha256 = "036xn22jkaf3akpid7w23b8vkqa3xxqz93mwacmyar5vw7slm3cv";
+    sha256 = "829fa113daed74398c49c3f2b7672807f58ba85d0fa463f5bc726e1b0138b86b";
   };
 
   nativeBuildInputs = [ pkgconfig ];
+  buildInputs = [ epoxy ];
 
   propagatedBuildInputs = [ glibmm gtk3 atkmm cairomm pangomm ];
 
   enableParallelBuilding = true;
   doCheck = true;
 
-  meta = {
+  meta = with stdenv.lib; {
     description = "C++ interface to the GTK+ graphical user interface library";
 
     longDescription = ''
@@ -34,9 +35,9 @@ stdenv.mkDerivation rec {
 
     homepage = http://gtkmm.org/;
 
-    license = stdenv.lib.licenses.lgpl2Plus;
+    license = licenses.lgpl2Plus;
 
-    maintainers = with stdenv.lib.maintainers; [ raskin urkud vcunat ];
-    platforms = stdenv.lib.platforms.unix;
+    maintainers = with maintainers; [ raskin vcunat ];
+    platforms = platforms.unix;
   };
 }