New ship submarine

[richjoregonstate]

• [x] Add a frontend button to trigger placement.
• [x] Add a checkbox for below water
• [x] In board.placeShip() Alter the code to change the occupied squares of the sub so that it can do proper out of bounds check.
• [x] Remove the overlap check as the sub can be under ships
• [x] Modify the overlap check so that other ships ignore the sub
• [x] Modify board.atack() to handle the captains quarters of the sub

[yorkal]

The submarine works!