Abstract events are bad, remove them!
Did something that irritated me for a very long time

Replaced the NexusServer.Instance with NexusServer.instance()

Now, code can't change the instance anymore :D
Implemented an proper getter for the EventBus
Removed unused class
Moved AuthenticationManager
Cryptography draft 1
Major authentication rework

This should be pretty much bug-free. Will test it more in the next week.