Oscrypto

- Added TLS functionality
- Added Python 2.6 support
- Added `asymmetric.Certificate.self_signed`
- Added "raw" RSA signing/verification to `asymmetric.rsa_pkcs1v15_sign()` and
`asymmetric.rsa_pkcs1v15_verify()` functions
- Fixes for compatibility bugs with OS X 10.7
- Fixes for compatibility bugs with pypy3
- Fixes for compatibility bugs with cffi 0.8.6

- `oscrypto.public_key` renamed to `oscrypto.asymmetric`
- `.algo` attribute of `asymmetric.PublicKey`, `asymmetric.PrivateKey` and
`asymmetric.Certificate` classes renamed to `.algorithm`
- `parse_public()`, `parse_private()`, `parse_certificate()` and
`parse_pkcs12()` all now return just an asn1crypto object instead of a
2-element tuple with the algorithm name
- Added the `asymmetric.generate_pair()` function
- Added the functions:
- `asymmetric.dump_certificate()`
- `asymmetric.dump_public_key()`
- `asymmetric.dump_private_key()`
- `asymmetric.dump_openssl_private_key()`
- Added the `kdf.pbkdf2_iteration_calculator()` function
- Added the `setup.py clean` command

- Initial release