Added tool menu and simple tutorial

I finally got around to doing a simple bit of UI to make the thingy a bit more accessible...

Optims for large MC worlds

Funny how when you return to something after a while you often see new optims right off the bat. These affected running very large worlds from Minecraft. 

Lua drives in-game UI

A technical detail, but lua is now able to load/unload UI and change cursor modes etc.