Tic-Tac-Toe Requirements

This is part of ../../Examples/TicTacToe-JavaFX-UnRedo

Tic-Tac-Toe is played on a grid of 3x3 cells. All cells begin as blank cells. Two players, the X-player, the O-player, alternate to place an X ("ex") or O (big-oh) in a blank-cell. Goal is to have 3 Xs or 3 Os in a row, in a column, or in a digonal. The first player to do so wins. A game is a draw if all 9 cells are filled without anyone winning. Often, we can detect a draw early – even before all 9 cells are filled.

This game is traditionally played on paper that passes between the players. Design and build an elegant version that can be played on a two networked computers.