rem: human_time (time_t const *t)
add: human_time (time_t t, int t_ns)
context: human_time (time_t const *t){  static char str[80];  struct tm *tm = localtime (t);  if (tm == NULL)    {      G_fail = 1;      return (char *) _("*** invalid date/time ***");    }  nstrftime (str, sizeof str, "%Y-%m-%d %H:%M:%S.%N %z", tm, 0, 0);  return str;}