Improve DiamondSnake / AppleSnake

[nitaku]

• [x] Use fruits
• [x] Grow the tail whenever a fruit is eaten
• [x] Lose 5 points (and tail length) when dying
• [x] Keep the minimum score at 1
• [x] Open the battlefield
  • [x] Fix the die outside Ship ref issue
• [ ] Consider destroying the old tail when the ship dies (vfx)
  • [ ] #705
• [ ] Change the battlefield shape
• [ ] Improve positions of spawners
• [ ] Improve fruit's fhufhufhu
• [ ] Alienize fruits
• [ ] Special fruits..?
• [ ] "gnam" sfx