Critical fix: a bizarre Bukkit bug was resulting in the /wb fill command sometimes wiping out the chunk at 0,0, even when that chunk was never even touched by the process. The bug is caused by Bukkit's World.unloadChunk() method, but the specific circumstances that result in it are unknown. The workaround fix applied in this release causes the task to speed along faster and memory usage to grow very quickly if you're running the fill task at a high frequency, so I've had to increase the "too low" memory threshold to 200 MB and increase the status update frequency and memory check to every 5 seconds (instead of every 10 seconds) to compensate.
The status update frequency for the trim task has likewise been switched to every 5 seconds, for consistency.
