Merge branch 'master' of https://github.com/erlehmann/minetest-delta.git into upstream_merge

Conflicts:
	.gitignore
	CMakeLists.txt
	data/heart.png
	src/CMakeLists.txt
	src/game.cpp
	src/guiMainMenu.cpp
	src/inventory.cpp
	src/map.cpp
	src/mapblock.cpp
	src/mapnode.cpp
	src/mapnode.h
	src/materials.cpp
	src/server.cpp

Signed-off-by: Sebastian Rühl <bahamada_basti@yahoo.de>