Entity damage system WIP; Remove C++ mobs

data/mods/default/init.lua

src/content_abm.cpp

src/content_cao.cpp

src/content_sao.cpp

src/content_sao.h

src/itemgroup.h

src/luaentity_common.cpp

src/luaentity_common.h

src/scriptapi.cpp

src/scriptapi.h

src/server.cpp

src/serverobject.h

src/serverremoteplayer.cpp

src/serverremoteplayer.h