Grass now grows under up-side-down slabs
Remove old function
Merge branch 'master' into Slabs

Conflicts:
	src/Blocks/BlockDirt.h
Add CanChangeDirtToGrass function to Block Handlers.
Merge branch 'master' into Slabs
Remove old import
Small changes
Some change to Entity.cpp

* Added comments to BroadcastMovementUpdate() and the collision tracer
Merge branch 'master' into fixes

Conflicts:
	src/World.h
Initial C++ SSL classes.
Authenticator uses some C++ SSL objects.
Attempted CMake inclusion for PolarSSL++.
Fixed filename case.
Declared a SharedPtr that hopefully resolves on all platforms.

MSVC2008 has it in std::tr1, all the others in std.
cByteBuffer uses void * instead of char * in data interface.

This makes it compatible with any pointer type.
Replaced MSVC-specific decorators with our universal ones.
Implemented suggestions
Added shared_ptr handling for C++03 mode.
Fixed C++11 check for SharedPtr.
Add entity invulnerable