Initial gitignore.
Tic Tac Toe game, initial commit.

This is a simple Tic Tac Toe game in C++.  It serves as a
demonstration of C++ techniques in implementing adaptable,
extensible, easy-to-maintain code.  I have mostly avoided
STL techniques, and templates, as the initial assignment
goal for my student was C++ inheritance and virtual
member functions.
Merge remote branch 'github/master' into tictactoe
Merge branch 'tictactoe'