Netcode + Balance improvements

-Fixed a bug which sometimes made the player not gain control after spawning in multiplayer. -Enemies with multiple machine guns can no longer fire invisible bullets in co op. -Enemy rocket artillery now looks cooler. -Missiles and Torpedoes can now slow down to turn, making them more accurate. -Some weapon balance improvements for deathmatch. -Improved bullet sprites for certain ammo types. -Tweaked enemy spawns in earth, phobos and asteroid field. -Plasma ammo moves faster but deals a little less damage. -Tactical nukes move much faster. -UI now scales when screen width goes below 1280.