ES6 Array goodies and Object fixes

Adding some ES6 polyfills!

* Converted all modules to UMD (experimental support for node.js!)
* ES6 Array.prototype.find() and Array.prototype.findIndex()
* ES6 Array.from() (without recent mapping functionality)
* ES6 Array.of()
* Fix for edge case of Object.getPrototypeOf (thanks Norman Xu!)
* Allow prototype extension for DOM objects in IE8 (thanks Norman Xu and Mikael Karon!)