If a plugin calls player.hidePlayer(other); then player.showPlayer(other);
in the same tick the other player will be added to the entity destroy queue
then a spawn packet will be sent. On the next tick the queue will be
processed and a destroy packet will be sent that renders the other player
invisible. To correct this we ensure the destroy queue is in sync with use
of the vanish API.
By: Travis Watkins <amaranth@ubuntu.com>
980784204e