Changes:
* Shortened a few messages
* Changed the finish hook from the load event to a straight function
call
* Tasks can now be retried
* Attempts to fix the thread synchronization issue

Notes:
ChunkIO is on another thread, I need to find some lock or something to
synchronize on.
Method waitForFinish() 'a()' in FileIOThread does not seem to entirely
work indicating something else at play.

If the world is not generating new chunks, or modifying old ones, no
errors will occur