Add Game struct. Laysdown work to add support for powerups.
Use Cell with z-layers for drawing.
Can pick powerups. Can place powerups. Powerups probs are messed.
Fix the probabilities. Works fine.
Refactor a bit. Still ~ugly.
Flames stop at first rock/powerup. Destroy rocks/powerups.
Remove debugging artifacts.
Try to refactor some more. Not working.
Fix bug of remniscent flame when two explosion occurs on same cell.
Merge pull request #7 from aybabtme/powerups

Add powerups, limit explosions to first explodable.