While the previous logic was logically correct, some CB API's before
would request a chunk without removing it from the unload queue.
While this is logically wrong, some plugins seem to be causing unload issues.
This change will make anything using that one API that use to not remove from
queue, no longer remove from queue.
Hopefully other activities on the server will touch the chunk if it REALLY is in use.
Use an optimized method to test if a block position meets a desired light level.
This method benefits from returning as soon as the desired light level matches.
Also Optimize Grass more
BlackHole
Shane Freeder
Zach Brown
Aikar