Feature: Editor Framework

[ColdenCullen]

This adds the beginnings of an editor framework. It adds:

• Vibe-d as a dependency
• Custom WebSocket server
• Framework for sending and receiving messages
• The ability to get a callback on a response
• The ability to respond to a received message

There's still lots to do for the tools framework, including a more useful front end framework, and more engine side hooks for actually changing things. That said, this will allow game teams to start setting up actual events.

[brooklynlittell]

Looks great! The callback stuff is nifty, and event registration looks solid. :+1: I had to fix the documentation typo; I would see it immediately when reading the code. :laughing: