Optimized chunk loader
Better StreamNextChunk() method
Merge branch 'master' into ChunkLoader
Stream 4 chunks per tick. Added priority.
Added distance check.
Merge branch 'master' into ChunkLoader

Conflicts:
	src/ClientHandle.cpp
New c++11 stuff.
Use two lists and 2 chunk send prioritys.
Fixed submodule downgrades
Reverted plugin remove
style.
Merge branch 'master' into ChunkLoader

Conflicts:
	src/World.h
ComposableGenerator: Removed nullptr initializers.
En masse NULL -> nullptr replace
Merge pull request #1559 from mc-server/nullptr

En masse NULL -> nullptr replace
Signs can be placed on wallsigns.

Fixes #1438
Merge pull request #1562 from mc-server/signplace

Signs can be placed on wallsigns.
Removed the "conditional expression is constant" warning.

MSVC spits out many of these on its own std libraries.
Fixed a crash in redstone simulator.
Merge branch 'master' into ChunkLoader

Conflicts:
	src/ChunkSender.cpp
	src/ClientHandle.cpp
	src/World.h