OpenSSL key loading implementation
Bump to 0.5
DSA support
Updated docstrings
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
Fixup how the digest algorithm is sent
Update docs
Bump to 0.5
Removed signer/verifier from signature algorithm
Separate ECC key material from operations
Add docs for EC numbers
Add __init__ arguments to docs