Fix Gates and Doors so that when they're added/removed many times in a row, clients near them don't get packed bombed

Situation: It's pretty much confirmed now that the way gates and doors work lag out clients, since clicking on a gate/door will "delete" the original and replace it with a door in the new location. The problem is the door isn't properly deleted, so doing this enough times will cause a player to lag out when entering the area.