Changed builderDefs to use composedArgsAndFun, reduced number of nulls, made overrides in builderDefsPackage to work in an intuitive manner.

svn path=/nixpkgs/trunk/; revision=12655

pkgs/tools/security/ssss/0.5.nix

@@ -1,5 +1,5 @@
-args : with args; with builderDefs {src="";} null;
-	let localDefs = builderDefs (rec {
+args : with args; with builderDefs;
+	let localDefs = builderDefs.meta.function (rec {
 		src = /* put a fetchurl here */
 		fetchurl {
 			url = http://point-at-infinity.org/ssss/ssss-0.5.tar.gz;
@@ -15,7 +15,7 @@ args : with args; with builderDefs {src="";} null;
 			ensureDir $out/bin $out/share/man/man1
 			echo -e 'install:\n\tcp ssss-combine ssss-split '"$out"'/bin' >>Makefile
 		'') ["minInit" "doUnpack" "defEnsureDir"];
-	}) null; /* null is a terminator for sumArgs */
+	});
 	in with localDefs;
 stdenv.mkDerivation rec {
 	name = "ssss-"+version;