Fixed m_SentChunks list chunk removing.
Update README.md
Fixed missing CS lock in cChunkMap::WakeUpSimulatorsInArea().
cLuaState: Fixed errors on non-existent callbacks.

This mostly affected table-based callbacks, such as the cLineBlockTracer. If a callback didn't exist, the code would still push its arguments on the stack, breaking the next callback.
Merge branch 'master' into GrownBiomes
GrownProt biome gen: Added biome edges.
GrownProt: Added the rest of rare and M biomes.