Create output for requesting shot coordinates from user.
Add GamePlayer as listener in GameBoard.
HumanPlayer informs user of hit.
Revert "HumanPlayer informs user of hit."

This reverts commit 4be7b09b523d81107102d7bf9eb650528fff6d56.
Revert "Add GamePlayer as listener in GameBoard."

This reverts commit 35c39fbb1f5f198f5d23802603e92503241d325d.
Add main method.