Log Message:
Update to 0.6:

0.6 - 2014-09-29
~~~~~~~~~~~~~~~~

* Added
  :func:`~cryptography.hazmat.primitives.serialization.load_pem_private_key` to
  ease loading private keys, and
  :func:`~cryptography.hazmat.primitives.serialization.load_pem_public_key` to
  support loading public keys.
* Removed the, deprecated in 0.4, support for the ``salt_length`` argument to
  the :class:`~cryptography.hazmat.primitives.asymmetric.padding.MGF1`
  constructor. The ``salt_length`` should be passed to
  :class:`~cryptography.hazmat.primitives.asymmetric.padding.PSS` instead.
* Fix compilation on OS X Yosemite.
* Deprecated ``elliptic_curve_private_key_from_numbers`` and
  ``elliptic_curve_public_key_from_numbers`` in favor of
  ``load_elliptic_curve_private_numbers`` and
  ``load_elliptic_curve_public_numbers`` on
  :class:`~cryptography.hazmat.backends.interfaces.EllipticCurveBackend`.
* Added
  \ 
:class:`~cryptography.hazmat.primitives.interfaces.EllipticCurvePrivateKeyWithNu \ 
mbers`
  and
  \ 
:class:`~cryptography.hazmat.primitives.interfaces.EllipticCurvePublicKeyWithNum \ 
bers`
  support.
* Work around three GCM related bugs in CommonCrypto and OpenSSL.

  * On the CommonCrypto backend adding AAD but not subsequently calling update
    would return null tag bytes.

  * One the CommonCrypto backend a call to update without an empty add AAD call
    would return null ciphertext bytes.

  * On the OpenSSL backend with certain versions adding AAD only would give
    invalid tag bytes.

* Support loading EC private keys from PEM.