Decentralized Auth

[DEATHB4DEFEAT]

First immediate step (not decentralized auth but still relevant) is we need an official SimpleStation authentication server set up and used by the launcher (and EE servers) by default. Need to figure out if using a separate auth server requires modifying the engine.

Should have a setup page like SSMV where the user is asked to make/login to their account(s, multiple sessions should be allowed) with a list of default servers (+ guest and maybe keys for MV support). At the end of the default auth server entries there should be one titled "homeserver"(?) that lets you pick an arbitrary auth server along with your username/password.