* Require window@4.2.6
* Set global properties as getters
Some properties will throw an error when accessed in certain conditions. We don't want to throw these errors, by accessing them when we setup the environemnt. Instead we should create getters for all window properties so they can throw the appropriate errors when accessed by user code.
* Update expectedProperties.json for window@4.2.6
Before we were manually grabbing `window._core` which was a bit of a hack. This sets the correct settings to allow us to get all globals with `Object.getOwnPropertyNames(window)`.
We also need to clone the settings object before passing it to jsdom otherwise it tacks loads of stuff on to the referenced object.
Luke Childs