7.ss, scheme.1.in, comments of many files original commit: 06f858f9a505b9d6fb6ca1ac97234927cb2dc641
github issue #77. io.c, schlib.c, thread.c original commit: fe172bfdfbf2f606db611013e7689d6a2b117d5e
original commit: 47a210c15c63ba9677852269447bd2f2598b51fe