dxflib: add the DXF format support library

pkgs/development/libraries/dxflib/default.nix

···
+{stdenv, fetchurl}: 
+
+stdenv.mkDerivation rec {
+  version = "2.5.0.0-1";
+  name = "dxflib-${version}";
+  src = fetchurl {
+    url = "http://www.qcad.org/archives/dxflib/${name}.src.tar.gz";
+    sha256 = "20ad9991eec6b0f7a3cc7c500c044481a32110cdc01b65efa7b20d5ff9caefa9";
+  };
+
+  meta = {
+    maintainers = with stdenv.lib.maintainers; [raskin];
+    platforms = stdenv.lib.platforms.linux;
+    description = ''DXF file format library'';
+  };
+}
+