Better chunk loading

5.1:
Fix post generation dropping items when placing invalid blocks

5.0:
Rewrite how chunk loading is handled to make it more server friendly and less prone to stalling.
Introduces two new speed modifiers to chunkloading which can be set in the config(slower = less lag)
Added new feature "optimizeWaiting" which makes the server thread stall less when directly waiting for a chunk to load.