Try communicating with brokers via default Node.js IPC instead of ncom (maybe)

[jondubois]

The ncom module was introduced into socketcluster and sc-broker before Node.js made it possible to pass socket handlers between different processes. Now that it is possible, consider switching to Node.js IPC instead of ncom (ncom uses UNIX domain sockets in Linux and named pipes in Windows).

Consider if an IPC solution is capable of dealing with and recovering from process failures. The IPC handle for the broker server will need to be passed to both the SC master process AND to each worker