Log Message:
Update to 2.5.5, a minor security fix release with very few changes relative to \ 
2.5.4.

(ok to update during freeze by wiz@)

Extension Modules
-----------------

- expat: Fix DoS via XML document with malformed UTF-8 sequences
  (CVE_2009_3560).

- expat: Fix DoS via malformed XML (CVE-2009-3720).

Core and builtins
-----------------

- Issue #6990: Fix threading.local subclasses leaving old state around
  after a reference cycle GC which could be recycled by new locals.

Library
-------

- Issue #7403: logging: Fixed possible race condition in lock creation.

- Issue #5068: Fixed the tarfile._BZ2Proxy.read() method that would loop
  forever on incomplete input. That caused tarfile.open() to hang when used
  with mode 'r' or 'r:bz2' and a fileobj argument that contained no data or
  partial bzip2 compressed data.