adding new libraries to try-eio

[zeroexcuses]

Short question: How do I modify try-eio (I have everything building locally) so the following lines can work:

open Js_of_ocaml
open Js_of_ocaml_lwt
open Lwt
open Js

Long question:

I want to be able to copy/paste https://github.com/ocsigen/js_of_ocaml/blob/master/examples/webgl/webgldemo.ml into the REPL, and then after making modifications to have the code run on the main DOM thread instead of a webworker, have it work.

Thanks!