* remove commented code
* serialize errors sent from http workers to the main process
* drop support for custom http headers set via config.js#httpHeaders
* websockets: only listen on localhost, respect websocketPort config in workers' proxy config
* use the nodejs cluster module to handle http traffic with multiple threads
* listen for websocket traffic on a new port because all such logic needs to share state
* proxy websocket URLs from the cluster to the new port so everything is backwards compatible
* implement logic for http workers to make requests and stay in sync with the main process
* unrelated: define the expected nodejs version in a constant
