added a method to create a clone.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@1352 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/util/ArgumentListBuilder.java

@@ -49,4 +49,10 @@ public class ArgumentListBuilder {
     public String[] toCommandArray() {
         return args.toArray(new String[args.size()]);
     }
+    
+    public ArgumentListBuilder clone() {
+        ArgumentListBuilder r = new ArgumentListBuilder();
+        r.args.addAll(this.args);
+        return r;
+    }
 }