Allows entities without names
Adds Submarine entity
Adds Storable.create
Uses geocell_root.cell for root cell of entities
Adds Player#fleet, #current_ship, #create_ship
Changes CSS class human to submarine
Entities now add themselves to their game
Moves the current ship along with each scan
Uses game.geocell_root; #move_to looks up cell if passed a string
Allows no name for Games; Uses #create for GeocellRoot and Player