0.22:
  - don't modify non-localized $_.  whoops.  (we don't want to mess
    with our caller's world)

0.21:
  - add missing EPOLLRDBAND, from Paul Visscher <paulv@canonical.org>

0.20:

  - on x86_64 detect 32-bit vs 64-bit process and use right syscall
    numbers.  previously worked only with 64-bit userland.

0.1:

  - first release.  epoll and sendfile only.  Linux only.