Change Minetest-c55 to Minetest

doc/protocol.txt

old/changelog.txt

src/activeobject.h

src/ban.cpp

src/ban.h

src/biome.cpp

src/biome.h

src/camera.cpp

src/camera.h

src/chat.cpp

src/chat.h

src/client.cpp

src/client.h

src/clientmap.cpp

src/clientmap.h

src/clientobject.cpp

src/clientobject.h

src/clientserver.cpp

src/clientserver.h

src/clientsimpleobject.h