revert lua lane to 2.0.3 as it seems to make stuff go wild :/

game/thirdparty/lanes-keeper.lua

game/thirdparty/lanes.lua

src/lualanes/lanes.c

src/lualanes/threading.c

src/lualanes/threading.h

src/lualanes/tools.c

src/lualanes/tools.h

src/main.c