#4 Server input event corrections

[Bryan Conrad]

The server will need to be able to perform the following operations in response to an event submitted as input from a client:

1. Acknowledge a correct event (simply rebroadcast it)
2. If event is invalid, reject it
3. If event is too old, revise the time on it and revalidate

Clients should maintain a mutable list of events occuring after the last saved state, and when receiving a response of type 2 or 3, revise the event queue and resimulate.