auto merge of #1689 : jdm/servo/unions, r=kmcallister

Seven hours on a train without internet will do this to you. Fixes #541.

src/components/script/script.rs

@@ -40,6 +40,8 @@ pub mod dom {
             pub mod PrototypeList;
             pub mod RegisterBindings;
             pub mod BindingDeclarations;
+            pub mod UnionConversions;
+            pub mod UnionTypes;
         }
     }