Tuto branch update.

A few weeks ago, I found myself pressing the direction pad of my DS to keep
that little character onscreen. It had the most basic behaviour could think of because its sole purpose was to demonstrate how we control things in my game engine. Somehow, it felt a bit like an empty level in Space Taxi.
today, that same character moves around a place that comes from the level editor, with blocking tiles effectively blocking you. What it misses is a target. Snake-like pellets, if you want.

That requires me to revise:
- collisions between Gobs
- counters
- in-game level changes.