Allow use of sha256 by code in the lua controller

[Darin755]

I was working on making some fun things with digilines and lua controllers when I discovered that there doesn't seem to be a way to do a sha256 hash from the lua controller.

What I am trying to build is a secure entrance that allows a player to either authencate with there username (player detector) and/or a password. I want this to be secure so I was hoping to hash the credentials. The idea is that even if a "bad guy" gets access to the lua controller they still will not have the password. This is overkill but I think that is part of the fun.