Update to 2.5
    
    - New upstream release 2.5:
      - Added PKCS#1 encryption schemes (v1.5 and OAEP); we now have a decent,
        easy-to-use non-textbook RSA implementation
      - Added PKCS#1 signature schemes (v1.5 and PSS); v1.5 required some
        extensive changes to Hash modules to contain the algorithm-specific ASN.1
        OID, and to that end we now always have a (thin) Python module to hide the
        one in pure C
      - Added 2 standard Key Derivation Functions (PBKDF1 and PBKDF2)
      - Added export/import of RSA keys in OpenSSH and PKCS#8 formats
      - Added password-protected export/import of RSA keys (one old method for
        PKCS#8 PEM only)
      - Added ability to generate RSA key pairs with configurable public
        exponent e
      - Added ability to construct an RSA key pair even if only the private
        exponent d is known, and not p and q
      - Added SHA-2 C source code (fully from Lorenz Quack)
      - Unit tests for all the above
      - Updates to documentation (both inline and in Doc/pycrypt.rst)
      - Minor bug fixes (setup.py and tests)
    - Upstream no longer ships python-3-changes.txt