* Tornado now depends on the `backports.ssl_match_hostname
  <https://pypi.python.org/pypi/backports.ssl_match_hostname>`_ when
  running on Python 2.  This will be installed automatically when using ``pip``
  or ``easy_install``
* Tornado now includes an optional C extension module, which greatly improves
  performance of websockets.  This extension will be built automatically
  if a C compiler is found at install time.

New modules
~~~~~~~~~~~

* The `tornado.platform.asyncio` module provides integration with the
  ``asyncio`` module introduced in Python 3.4 (also available for Python
  3.3 with ``pip install asyncio``).

`tornado.auth`

* ``TracebackFuture`` now accepts a ``timeout`` keyword argument (although
  it is still incorrect to use a non-zero timeout in non-blocking code).

``tornado.curl_httpclient``

* `.xhtml_escape` now escapes apostrophes as well.
* `tornado.escape.utf8`, `.to_unicode`, and `.native_str` now raise
  `TypeError` instead of `AssertionError` when given an invalid value.

`tornado.gen`
~~~~~~~~~~~~~

* Coroutines may now yield dicts in addition to lists to wait for
  multiple tasks in parallel.
* Improved performance of `tornado.gen` when yielding a `.Future` that is
  already done.

`tornado.httpclient`

* Malformed ``x-www-form-urlencoded`` request bodies will now log a warning
  and continue instead of causing the request to fail (similar to the existing
  handling of malformed ``multipart/form-data`` bodies.  This is done mainly
  because some libraries send this content type by default even when the data
  is not form-encoded.
* Fix some error messages for unix sockets (and other non-IP sockets)

`tornado.ioloop`
~~~~~~~~~~~~~~~~

* `.IOLoop` now uses ``IOLoop.handle_callback_exception`` consistently for
  error logging.
* `.IOLoop` now frees callback objects earlier, reducing memory usage
  while idle.
* `.IOLoop` will no longer call `logging.basicConfig` if there is a handler
  defined for the root logger or for the ``tornado`` or ``tornado.application``
  loggers (previously it only looked at the root logger).

`tornado.iostream`
~~~~~~~~~~~~~~~~~~

* `.IOStream` now recognizes ``ECONNABORTED`` error codes in more places
  (which was mainly an issue on Windows).
* `.IOStream` now frees memory earlier if a connection is closed while
  there is data in the write buffer.
* `.PipeIOStream` now handles ``EAGAIN`` error codes correctly.
* `.SSLIOStream` now initiates the SSL handshake automatically without
  waiting for the application to try and read or write to the connection.
* Swallow a spurious exception from ``set_nodelay`` when a connection
  has been reset.

`tornado.locale`
~~~~~~~~~~~~~~~~

* `.Locale.format_date` no longer forces the use of absolute
  dates in Russian.

`tornado.log`
~~~~~~~~~~~~~

* Fix an error from `tornado.log.enable_pretty_logging` when
  `sys.stderr` does not have an ``isatty`` method.
* `tornado.log.LogFormatter` now accepts keyword arguments ``fmt``
  and ``datefmt``.

`tornado.netutil`
~~~~~~~~~~~~~~~~~

* `.is_valid_ip` (and therefore ``HTTPRequest.remote_ip``) now rejects
  empty strings.
* Synchronously using `.ThreadedResolver` at import time to resolve
  a unicode hostname no longer deadlocks.

`tornado.platform.twisted`

* `.Subprocess` no longer leaks file descriptors if `subprocess.Popen` fails.

``tornado.simple_httpclient``

* `.StaticFileHandler` no longer fails if the client requests a ``Range`` that
  is larger than the entire file (Facebook has a crawler that does this).
* `.RequestHandler.on_connection_close` now works correctly on subsequent
  requests of a keep-alive connection.
* New application setting ``default_handler_class`` can be used to easily
  set up custom 404 pages.
* New application settings ``autoreload``, ``compiled_template_cache``,
  ``static_hash_cache``, and ``serve_traceback`` can be used to control
  individual aspects of debug mode.
* New methods `.RequestHandler.get_query_argument` and
  `.RequestHandler.get_body_argument` and new attributes
  ``HTTPRequest.query_arguments`` and ``HTTPRequest.body_arguments`` allow access
  to arguments without intermingling those from the query string with those
  from the request body.
* `.RequestHandler.decode_argument` and related methods now raise
  an ``HTTPError(400)`` instead of `UnicodeDecodeError` when the
  argument could not be decoded.
* `.RequestHandler.clear_all_cookies` now accepts ``domain`` and ``path``
  arguments, just like `~.RequestHandler.clear_cookie`.
* It is now possible to specify handlers by name when using the
  `tornado.web.URLSpec` class.
* `.Application` now accepts 4-tuples to specify the ``name`` parameter
  (which previously required constructing a `tornado.web.URLSpec` object
  instead of a tuple).
* Fixed an incorrect error message when handler methods return a value
  other than None or a Future.
* Exceptions will no longer be logged twice when using both ``@asynchronous``
  and ``@gen.coroutine``


`tornado.websocket`

* `.WSGIContainer` now calls the iterable's ``close()`` method even if
  an error is raised, in compliance with the spec.