gamejs-cadaver package

[oberhamsi]

provide "gamejs-cadaver" package to be used as a starting point for games. the code is already in the games and tutorials, we just need put it in a coherent package.

do not get fancy about all of this. it's all throw-away, getting-started-fast code. I would expect most if not all parts of gamejs-cadaver to be replaced by custom code for anything but trivial games.

• director and a start scene class and game scene
• animation and spritesheet classes

would be nice but not as easy to extract:

• game scene is: tmx scrolling engine scene with a collision model
• basic actor (like we had in early gamejs.. it was called SimpleSprite or smth)
• actor A* on tmx collision model (could also be used to showcase worker for A*)