ChunkManager optimize chunks handling in small and big worlds
Small worlds gets benefits with using int-object map instead long-object (in area -32768...32767 by x and z)
Large worlds gets benefits by using efficient map by Colt project, which a little (3-6%) slower in writing, but greatly faster
(400-500% from Java's HashMap and 150-180% from Trove's maps) on reading.
* Clear outgoing packet queue after player disconnect
* Disable sleep between chunk saving
* Put 2x4096 bytes instead 2048x4 bytes for region file aligment
* Using map to search player by name instead iterating over all players
* Some tweaks for decorations (item frames, maps)
