Hooks for "addEventListener" and "removeEventListener" are wrongly depending on "this"

[weizman]

If you look at listeners.js#L30 and listeners.js#L41 you'd see that in both addEventListener and removeEventListener listeners patches the call for the native functions rely on this being the this value of the call.

So if you call {window/document/document.body}.{addEventListener/removeEventListener}('some_event', () => {}) it'll work, but if you do {addEventListener/removeEventListener}('some_event', () => {}) the this will resolve to undefined even though it should be window.

This needs to be fixed.

[weizman]

fixed #40