Adding particle blend, glow and animation (#4705)

builtin/common/misc_helpers.lua

doc/lua_api.txt

src/client.h

src/network/clientpackethandler.cpp

src/nodedef.cpp

src/nodedef.h

src/particles.cpp

src/particles.h

src/script/common/c_content.cpp

src/script/common/c_content.h

src/script/common/c_converter.cpp

src/script/common/c_converter.h

src/script/lua_api/l_particles.cpp

src/server.cpp

src/server.h