* Fixed handling of closed connections with the ``epoll`` (i.e. Linux)
  ``IOLoop``.  Previously, closed connections could be shut down too early,
  which most often manifested as "Stream is closed" exceptions in
  ``SimpleAsyncHTTPClient``.
* Fixed a case in which chunked responses could be closed prematurely,
  leading to truncated output.
* ``IOStream.connect`` now reports errors more consistently via logging
  and the close callback (this affects e.g. connections to localhost
  on FreeBSD).
* ``IOStream.read_bytes`` again accepts both ``int`` and ``long`` arguments.
* ``PeriodicCallback`` no longer runs repeatedly when ``IOLoop`` iterations
  complete faster than the resolution of ``time.time()`` (mainly a problem
  on Windows).

Backwards-compatibility note