[Permissions] Add admin / superadmin groups and commands

[captbunzo]

Okay, so apparently on Shardscape there is a thing where admins and super admins are a different thing. And they can set their actual permissions so that they can play honestly in the survival world without creative and what not. And all they have to do to get their admin special type powers back is type a command.

We should add this to Nyvaria (for admins to choose to use, or not, at their discretion).