weapon independency fixes

Damage() function now checks that the target entity does not have a realowner which is another independent player before dealing damage and/or force to it

fireball's primary BFG no longer tries to target independent players

fireball's secondary "turrets" no longer try to target independent players

they also ignore frozen players as suggested by terence

electro's primary's explosion no longer explodes electro balls owned by other independent players

electro's primary's midair combo no longer explodes electro balls owned by other independent players

electro's comboexplosion no longer explodes electro balls owned by other independent players