"Connect 4" game.

A classic "Connect 4" board game, created in KoGaMa. RULES: 1. Yellow always start first. 2. Players must connect 4 of the same colored discs in a row to win. 3. Only one piece is played at a time. 4. Players can be on the offensive or defensive. 5. The game ends when there is a 4-in-a-row or a stalemate. 6. RESET GAME ONLY WHEN THE WINNER IS DETERMINED. Responsible for design and logic: Svor. (Thanks to ash for fixing some game problems.)