mate: remove major-ver and minor-ver

Keep only the version atribute in derivations, with the full version
string of the package. This will make it easier to write a script for
automatic updating of the packages using the update-source-version
command from common-updater-scripts.

pkgs/desktops/mate/mate-backgrounds/default.nix

@@ -1,13 +1,11 @@
-{ stdenv, fetchurl, intltool }:
+{ stdenv, fetchurl, intltool, mate }:
 
 stdenv.mkDerivation rec {
   name = "mate-backgrounds-${version}";
-  version = "${major-ver}.${minor-ver}";
-  major-ver = "1.18";
-  minor-ver = "0";
+  version = "1.18.0";
 
   src = fetchurl {
-    url = "http://pub.mate-desktop.org/releases/${major-ver}/${name}.tar.xz";
+    url = "http://pub.mate-desktop.org/releases/${mate.getRelease version}/${name}.tar.xz";
     sha256 = "06q8ksjisijps2wn959arywsimhzd3j35mqkr048c26ck24d60zi";
   };