Added a RemoveIf() function to cQueue
Lighting thread: skip chunks that are already lit.
Added a cWorld:PrepareChunk function.

It prepares the chunk - loads or generates it and lights it.
The spawn prepare process uses this function.
Merge pull request #1657 from mc-server/PrepareChunk

Prepare chunk
Debuggers: Changed to use Info.lua file.
Debuggers: Added loadchunk and preparechunk commands.

preparechunk is not working yet because the required API is missing.
Exported cWorld:PrepareChunk to Lua API, test in Debuggers.
LightingThread: Fixed a memory leak.
Updated the Core.