Added 2nd player detection

Now assigns "X" to first entrant, "O" to second.
Marks array based on which player submitted.
Added grid & misc updates

3x3 grid to represent play board is now included.
Player identification on start now included.
Clicking on grid sends id of box clicked, that id is then interpreted to
adjust the board array.
DisplayArray function adjusted to output to grid instead of debug text.
Message input box and send button removed.