Changed the signature of get_reachable_cells to take a ship and not a position.
Changed line of sight so that all ships block line of sight.
Reworked on ModWeapon, so that the rate of fire increase can now go from any fractions up. For instance starting with 2/7, we will have 3/8, 4/9, 1/2, 2/3, ...
Disable Boost Speed when ship moved and Boost Weapon when ship attacked.