encoding-indexes aren't properly loaded

Getting `Uncaught TypeError: Cannot read property 'ibm866' of undefined` error in client-console. It's likely an issues occurs due to [expectation](https://github.com/inexorabletash/text-encoding/blob/master/lib/encoding.js#L11) that `encoding-indexes.js` returns an object with encoding-indexes whereas it assigns them to global object.
