Address some chunk gen speed issues - see below for current reasoning.

As of 1.7, Mojang added a check to make sure that only chunks which have been lit are sent to the client. Unfortunately this interferes with our modified chunk ticking algorithm, which will only tick chunks distant from the player on a very infrequent basis. We cannot unfortunately do this lighting stage during chunk gen as it appears to put a lot more noticeable load on the server, than when it is done at play time. For now at least we will simply send all chunks, in accordance with pre 1.7 behaviour.