Remove __proto__ use from zepto.

This addresses #970 by removing the need to use `__proto__` and instead relying on a technique that more closely resembles jQuery. This also avoids the need for a fallback for IE<11. Tested this with `npm test` as well.
PhantomJS was erroring and I narrowed it down to the array-like object of zepto and not issues with arrays or nodelists and have modified the lines in question.