[ssssss] AI System

[miketvo]

Child of #65

To do:

Implement an AI system for the AI snakes in Chaos mode.

Needed AI algorithms:

• PlayerSnakeAgent (player controlled).
• HungrySnakeAgent (always head for the closest food cell regardless of the food value, without regard to its own safety).
• HangrySnakeAgent (tries to grow itself to a certain length, then tries to kill the closest snake without regard to its own safety).
• BalancedSnakeAgent (tries to balance growing and killing the player/other snakes).
• QLSnakeAgent (applies Q-learning, complete with developer-only training mode that produces a Q-table that would be used for regular games).

References:

• UC Berkeley CS188 Intro to AI -- Course Materials
• Artificial Intelligence: A Modern Approach, 4th Global ed.
• Artificial Intelligence for Games 2nd Edition
• AI for Game Developers
• cfoh/snake-game