I did one structural change to the way ship_fireBullet works. It
previously had two separate places for reducing ammo from the player.
I changed this so that it removes ammo in the same place regardless
of which weapon it is, but then performs the plasma "out of ammo"
action afterwards. It seems to work properly.
Also fixed a flaw in the saving which would in some cases cause
the stationed planet to not get saved properly.