Speedup getBlockNodeIdMapping by up to factor 4 by using a fixed size mapping array
Speedup getTileInfo by up to 30%
Use memset for flag initialization (compiler optimization is way better)
use temp variables instead of recalculating array index
Speedup attachement handling by replacing vector search by direct array access and secondary child lookup vector
Avoid doing a full material compare if not even first texture does match
Don't keep temporary images in RAM
Minor fix in check order
Remove emerge and speedup addArea by using memcopy instead of one by one assignment
Remove MapVoxelManipulator not really used by anyone
Fix race condition on accessing m_time_of_day_speed causing day night race on some architectures
Merge remote-tracking branch 'minetest/master'

Conflicts:
	src/clientmap.cpp
	src/map.cpp
	src/mapblock_mesh.cpp
	src/tile.cpp
Fix mod tab
Merge remote-tracking branch 'origin/master'
Fix Windows build
Merge remote-tracking branch 'minetest/master'

Conflicts:
	src/cguittfont/irrUString.h
	src/environment.cpp
	src/environment.h
Merge remote-tracking branch 'upstream/master' into next
Merge remote-tracking branch 'freeminer/next' into freeminer_next