Gomoku Game

This is a program that plays a variant on the game tic-tac-toe. It uses
a 5 x 5 board with a win condition of 4 in a row (compared to
tic-tac-toe that uses a 3 x 3 board with a win condition of 3 in a
row). The game involves a human player versus a computer AI. The moves
made by the AI are decided using a binary tree and alpha-beta pruning.