OpenSSL key loading implementation
Bump to 0.5
DSA support
Updated docstrings
add AES CTR support to OpenSSL 0.9.8
add changelog entry
allocate only 16 bytes

cffi allocates 17 bytes (one for trailing null), but that isn't
used by this function so we don't need to allocate it.
add some comments to explain the existence of AESCTRCipherContext
add test to verify AES CTR is always available in 0.9.8+, comment updates
rename all the things if you want them to work
Merge pull request #1068 from reaperhulk/ctr-mode-098

AES CTR Mode 0.9.8 Support
fix changelog to link to hkdfexpand
Merge pull request #1069 from reaperhulk/fix-hkdfexpand-changelog

fix changelog to link to hkdfexpand
load the openssl version text based on the loaded library
Merge pull request #1072 from reaperhulk/fix-1071

Make the OpenSSL version text reflect the loaded library
Merge pull request #959 from public/openssl-loading-backend

OpenSSL loading backend
Elliptic curve interfaces
Use @six.add_metaclass(abc.ABCMeta)
Add signing and verifying interfaces
Flesh out EllipticCurveSignatureAlgorithm