[ENH] Open iris with correct code

[ookamidev]

I have heard that iris will be added soon (I hope that pegasus gate shield will be also added). What about adding something that was SG-1 and Atlantis expedition using? A devide that sends for example 4-digit code (numbers) throught the gate to the other one and if the code is correct, it would open iris/shield, if not, iris/shield will stay closed. It could be done for example with OpenComputers? Or right inside of the gate? For example using and upgrade to add that menu? Also it would be nice to be able to add multiple codes if there will be more players.