Godmode, logout, fixing reloads, and other small improvemnts

This time I properly implemented god mode by adding more listeners. Unauthenticated players cannot be damaged, and mobs do not target them either.

The logout command was fixed by re-adding the player to the auth list and terminating their session if applicable, thus blocking all the relevant events. However, they are not teleported as this would cause them to lose their location upon reconnect.

Reloading no longer allows unauthenticated players to bypass the plugin, since the auth list is now saved to disk during onDisable and loaded again from onEnable.

Other small fixes include filtering the passwords from the server log and replacing the log messages with better ones, fixing some unclear command instructions in plugin.yml, and setting the player's oxygen level to full upon authentication so that they do not take drowning damage (there is no event for entity oxygen decrease). The minor refactored methods such as rehabPlayer and debilitatePlayer still exist and still work properly. Finally, the /lac rmpass command no longer requires lowercase usernames.

I think you'll find this much more satisfactory than my old hackish methods. Apart from my own testing, I have been using this on my main server for a while and my players haven't had any problems.