0.17:
  add Linux SIGIO support to IO
  expand IO api to be able to cope with edge triggered event
    notification: introduce io_eagain
  the integer scan routines should only write *dest if they actually
    scanned something
  io_sendfile and iob_send should return -1 to -3 just like io_trywrite
  make io_waituntil actually take an "until", not a "how long"
  turns out that BSD kqueue is actually Free/OpenBSD kqueue -- NetBSD
    doesn't have it.  That means I'll need some adaptive two-threads-
    running-poll approach to get C10k type scalability on NetBSD :-(
  turns out that BSD sendfile is actually FreeBSD sendfile -- neither
    OpenBSD nor NetBSD have it (as of 3.4 and 1.6.1).  That means I'll
    need to try using mmap on OpenBSD and NetBSD to get zero-copy TCP.
  guard against same event being signalled twice (confused our list
    handling)
  add support for Solaris /dev/poll
  add lose32 support (broken, please don't use!)
  head -1 -> head -n 1
  apending 0 bytes to an empty array would fail it
  remove socket_sendfile now that we have io_sendfile
  break out alloca #include dependency into havealloca.h
  support HP-UX sendfile64 (thanks to Rolf Eike Beer)
  support Solaris sendfile64
  support MacOS X sendfile (and comment it out again, the headers
    declare it but it's not actually there) (thanks to Bernhard Schmidt)
  support AIX 5 (thanks to Lutz Chwala and Arthur Erhardt)
  fix ip6_fmt (martin paljak)