Add ability to get/set HTTP response reason phrase in RequestHandler and HTTPResponse
simple_httpclient: Report errno and reason for connection errors.

Previously, this reported "Connection closed" for everything. This change
adds the exception info: HTTP 599: [Errno 61] Connection refused
Add binary_form argument to get_ssl_certificate.

The default form contains only basic information; the binary form is more
complete.
Reorganize IOStream tests and run them in both regular and ssl mode.

In the process, discover a quirk of the server-side SSL handshake and
a possible bug with ssl in pypy.
Allow calls to SSLIOStream.write while the connection is in progress.

Skip fast-path writes while connecting, and rework the interaction
between base class and subclass to avoid the possibility of doubly-wrapped
sockets.

Closes #587.
When closing an HTTPConnection, also clear a circular reference to self.

This reference could cause garbage collection of the connection object
to be delayed.

Closes #586.
Merge remote-tracking branch 'evanj/master' into merge
Fix test for pre-2.7 assertions
Release note updates
Make authdemo's logout less confusing.

Closes #376.
Make the openid claimed_id available in OpenIDMixin

This should be used as a persistent identifier for the user
since it is the only field guaranteed not to change.

Closes #568.
Refactor template namespace from render_string to its own method.

This method may be overridden as an alternative to overriding render_string
and adding to kwargs, or may be used directly to render templates
without going through render_string (as when templates are constructed
directly; see https://github.com/facebook/tornado/issues/564)
Fix template errors with empty blocks.

Emits a "pass" statement in every generated block whether it's empty or not;
I verified with the disassembler that the unnecessary pass statements
don't generate extra bytecodes.

Closes #546.
Release note updates
Don't let autopep8 rewrite all the lines longer than 80 chars.
Autopep8 cleanups.
Run twisted tests in a temporary directory so they don't leak temp files.

This mainly affected the unix socket tests.
Fill in missing docs and other minor doc updates.
Document all available application settings.
Organize next-release notes.