Remove the 'pub use self::BindingDeclarations::*;' export.
Point it to InterfaceTypes.rs directly to export generated types.
auto merge of #2290 : saneyuki/servo/export, r=jdm

- Fix #2128
- Take over from #2220

I didn't change `InterfaceTypes.rs` to `type.rs` because `type` is very common name which might be troublesome.