Redis

* Removed socket retry logic in Connection. This is the responsibility of
the caller to determine if the command is safe and can be retried. Thanks
David Wolver.
* Added some extra guards around various types of exceptions being raised
when sending or parsing data. Thanks David Wolver and Denis Bilenko.

* Imported with_statement from __future__ for Python 2.5 compatibility.

* Fixed a bug where some connections were not getting released back to the
connection pool after pipeline execution.
* Pipelines can now be used as context managers. This is the preferred way
of use to ensure that connections get cleaned up properly. Thanks
David Wolever.
* Added a convenience method called transaction() on the base Redis class.
This method eliminates much of the boilerplate used when using pipelines
to watch Redis keys. See the documentation for details on usage.

* Variadic arguments for SADD, SREM, ZREN, HDEL, LPUSH, and RPUSH. Thanks
Raphaël Vinot.
* (CRITICAL) Fixed an error in the Hiredis parser that occasionally caused
the socket connection to become corrupted and unusable. This became
noticeable once connection pools started to be used.
* ZRANGE, ZREVRANGE, ZRANGEBYSCORE, and ZREVRANGEBYSCORE now take an
additional optional argument, score_cast_func, which is a callable used
to cast the score value in the return type. The default is float.
* Removed the PUBLISH method from the PubSub class. Connections that are
[P]SUBSCRIBEd cannot issue PUBLISH commands, so it doesn't make sense
to have it here.
* Pipelines now contain WATCH and UNWATCH. Calling WATCH or UNWATCH from
the base client class will result in a deprecation warning. After
WATCHing one or more keys, the pipeline will be placed in immediate
execution mode until UNWATCH or MULTI are called. Refer to the new
pipeline docs in the README for more information. Thanks to David Wolever
and Randall Leeds for greatly helping with this.

* The PythonParser now works better when reading zero length strings.

* Fixed a typo introduced in 2.4.3