* automatically open the door of a portal that is freshly activated
* save portal pairs to disk and reload them on restarting the server
* teleport from one to the other a set time after entering a teleportation chamber and closing the door
* automatically open the door after effects wear off
* close the door on the other side when someone shuts the door
* teleport everyone inside the portal, not just the person who closed the door
* interrupt teleportation if portal is destroyed mid-teleportation
* cancel teleportation if someone moves out of the teleporter during teleportation (maybe prevent them from starting?)
* save any effects that would be overwritten by teleportation (including to disk!), and put them back when the player opens the door or arrives
* add portal particles and ambient sounds to the teleporter when portals are paired