So I am thinking that we should not disable the possibility for add-ons devs to make and ship their own options.xul file, so we need some way to determine if the options uri is made by us or not.  It does seem that using an `id` on the `<placeholder>` element would not work I agree, so perhaps we can use a `<setting>` node with the same idea, we should add a `data-jetpack-id=".."` in there too.