Send message to client on queue item timeout

I added emitting a message to the client on an item timeout so that the client could abort the request. Before, the server would correctly abort the request and send a 503, but the client would continue to process the request for as long as it took. This fix allows the client to listen and cancel any request for that item that it has in flight.

Also, some small cleanup/fixes and incremented the version for npm publish.

Thanks!