Log Message:
Update to 0.20.2:

0.20.2 (2014-06-16)
===================

Features added
--------------

* Some optimisations for set/frozenset instantiation.

* Support for C++ unordered_set and unordered_map.

Bugs fixed
----------

* Access to attributes of optimised builtin methods (e.g.
  ``[].append.__name__``) could fail to compile.

* Memory leak when extension subtypes add a memory view as attribute
  to those of the parent type without having Python object attributes
  or a user provided dealloc method.

* Compiler crash on readonly properties in "binding" mode.

* Auto-encoding with ``c_string_encoding=ascii`` failed in Py3.3.

* Crash when subtyping freelist enabled Cython extension types with
  Python classes that use ``__slots__``.

* Freelist usage is restricted to CPython to avoid problems with other
  Python implementations.

* Memory leak in memory views when copying overlapping, contiguous slices.

* Format checking when requesting non-contiguous buffers from
  ``cython.array`` objects was disabled in Py3.

* C++ destructor calls in extension types could fail to compile in clang.

* Buffer format validation failed for sequences of strings in structs.

* Docstrings on extension type attributes in .pxd files were rejected.