Working integrated server-client in-process RPC

[eigenraven]

This implements a working in-process client-server RPC communication socket, including an authentication handshake and passing a simple "chat" message from the client to the server as an example/test of how to use it.

[eigenraven]

Worldgen can be moved separately, I'm trying to avoid change-the-entire-world PRs to make reviewing much easier. And it is my plan to work on server chunk generation/streaming soon

[screret]

Kk cool