Allow variables to be overridden on the command line.

util/files.pl

@@ -4,6 +4,12 @@
 # It is basically a list of all variables from the passed makefile
 #
 
+while ($ARGV[0] =~ /^(\S+)\s*=(.*)$/)
+	{
+	$sym{$1} = $2;
+	shift;
+	}
+
 $s="";
 while (<>)
 	{
@@ -33,7 +39,7 @@ while (<>)
 		$o =~ s/\s+/ /g;
 
 		$o =~ s/\$[({]([^)}]+)[)}]/$sym{$1}/g;
-		$sym{$s}=$o;
+		$sym{$s}=$o if !exists $sym{$s};
 		}
 	}