Moving #include <stdio.h> into _scm.h

[Keisuke Nishida]

79 of 102 C files in libguile include <stdio.h>.

  % cd libguile
  % ls *.c | wc -l
      102
  % grep 'include <stdio.h>' *.c | wc -l
       79

Isn't it enough number to move them into _scm.h?

I also want to include at least <string.h> in _scm.h.
May I do that?

Kei