Simple but complete interactive mouse menu system demo.
Feel free to reuse it, but please credit me. The code is, I think well enough commented, will try to write a tutorial.
Features:
* It Use _G to access function and variables from their name, this simplify greatly management
* Menu is alway 100% visible
* called by right mous button, change with left, this allow to change several things with only one opening
* Can call functions
* Can change boolean state and display their state (here with a led
* Can display sprites
* Can change background color