Board has method for getting ships from ShipPlacer.
GameBoard has constructor for initial (empty) board.
Guice creates GameBoard using BoardFactory.
Remove interface for GridSquare.
Scanner is bound to System.in
Guice creates HumanPlayer through GamePlayerFactory.
Move user prompting into UserInterface.
Reduce visibility of methods in ScannerInterface.
Create interface for output, created using Guice.
Create package for user interface.