Try using rollup with plain es2015 modules (commonjs for bind-imgui)

Very simple setup with systemjs. Doesn't load modules, doesn't rollup yet

Actually call init() on window load

Test index.html and main.ts file just to load up ImGui. May have to switch the module setup on imgui-js to not use systemjs, and go with something browserify-compatible

Start work on implementing the 7gui exercises with typescript and a webgl IMGUI