First steps of &JSRef -> JSRef conversion

Replace &JSRef with JSRef in the bulk of the generated code. This will
remove a level of indirection throughout all DOM code.

This patch doesn't change methods implemented on JSRef<T> to take `self`
rather than `&self`, and it leaves a few other uses of &JSRef, but those
changes can be made incrementally.

components/script/dom/workerlocation.rs

@@ -29,9 +29,9 @@ impl WorkerLocation {
         }
     }
 
-    pub fn new(global: &JSRef<WorkerGlobalScope>, url: Url) -> Temporary<WorkerLocation> {
+    pub fn new(global: JSRef<WorkerGlobalScope>, url: Url) -> Temporary<WorkerLocation> {
         reflect_dom_object(box WorkerLocation::new_inherited(url),
-                           &Worker(*global),
+                           &Worker(global),
                            WorkerLocationBinding::Wrap)
     }
 }