Actual core engine code for Ranvier game engine.

Developing

• Have a checkout of the normal ranviermud repo
• Have a checkout of this repo adjacent to it
• In this repo run npm install then npm link (might need sudo)
• Go back to the other repo and run npm link ranvier

Now any changes you make in this repo will automatically be available inside your ranvier project. Any time you do npm install or npm update in your ranviermud repository you'll have to re-run npm link ranvier to re-establish the link.