Adding SEED cipher algorithm to openssl backends
add SEED docs, tests, small fixes
some small doc fixes
Merge pull request #909 from reaperhulk/doc-improvements

some small doc fixes
Merge pull request #908 from reaperhulk/seed-support

SEED support
ECDSA vector loader
Merge pull request #911 from public/ecdsa-vector-loader

ECDSA vector loader
prelim OAEP and PKCS1v15 for openssl 1.0.0+ and 0.9.8. decryption only
docs, tests, general huge improvements to RSA decryption
split 0.9.8 and evp_pkey_ctx branches into separate methods
fix indentation
update docs for OAEP
add InvalidDecryption exception, check for ct > key size
test should check for the right exception
register the EVP_PKEY_CTX for gc
more testing for rsa decrypt
improve comment based on review