Addressing a couple issues that were found.
-Fixed: WorldBorder prepare value is now calculated correctly.
-Removed: Pregenerator was doing duplicated work that could lag enough to lead to crashes.
-Changed: Pregenerator now 4x slowly unloads fully generated chunks to reduce strain on mcs saving system.
-Fixed: Preview Button was baldy aligned at More World Options screen.
-Fixed: Potential Crash after the pregeneration was finished.
-Fixed: Normal Gen would fill up the worldgen threadqueue so much that it wasn't able to provide for the game anymore. (Now on dedicated thread worker)
-Added: Some more information into the Log Spam.