Update or write rust bindings for duktape

[creationix]

No description provided.

[Fishrock123]

Can be found in https://github.com/nucleus-js/rustyduk/blob/master/src/duk_api.rs with https://github.com/nucleus-js/rustyduk/blob/master/src/duk_rust_link.c used to handle apis defined in the C header.

I don't think it is worth maintaining a separate crate for this, writing the bindings is pretty easy, consumes little time, and this means we can customize those a bit for our usage where it makes sense.