Added missing objects and methods to the JavaScript wrapper according to...

... Mozilla documentation https://developer.mozilla.org/en-US/docs/Web/API/Window

Hi, this pull request add some missing methods and objects to the JavaScript wrapper. I'm working on a large WebGL project and this is the changes that I needed to add to Ejecta to have my application working with it (wanaplan.com). Feel free to tell me if i'm wrong and I'll correct my PR quickly.