Fixes for some weird but crucial bugs in JS

js-library-glitch-fixes.js

//Polyfill for aframe/threejs raycasting
//navigator.xr.requestDevice is not a function
//see https://github.com/aframevr/aframe/issues/4354#issuecomment-567052948
  
navigator.xr.requestDevice = navigator.xr.requestDevice || function () {
  return new Promise((resolve, reject) => {
    resolve({
      supportsSession: new Promise((resolve, reject) => {
        resolve({
          immersive: true,
          exclusive: true
        });
      })
    });
  });
};