- Update of the underlying OpenSSH to 6.5p1

- Update to 6.5p1
Features since 6.4p1:
* ssh(1), sshd(8): support for key exchange using ECDH in
Daniel Bernstein's Curve25519; default when both the client
and server support it.
* ssh(1), sshd(8): support for Ed25519 as a public key type fo
rboth server and client. Ed25519 is an EC signature offering
better security than ECDSA and DSA and good performance.
* Add a new private key format that uses a bcrypt KDF to better
protect keys at rest. Used unconditionally for Ed25519 keys,
on demand for other key types via the -o ssh-keygen(1)
option. Intended to become default in the near future.
Details documented in PROTOCOL.key.
* ssh(1), sshd(8): new transport cipher
"chacha20-poly1305@openssh.com" combining Daniel Bernstein's
ChaCha20 stream cipher and Poly1305 MAC to build an
authenticated encryption mode. Details documented
PROTOCOL.chacha20poly1305.
* ssh(1), sshd(8): refuse RSA keys from old proprietary clients
and servers that use the obsolete RSA+MD5 signature scheme.
It will still be possible to connect with these
clients/servers but only DSA keys will be accepted, and
OpenSSH will refuse connection entirely in a future release.
* ssh(1), sshd(8): refuse old proprietary clients and servers
that use a weaker key exchange hash calculation.
* ssh(1): increase the size of the Diffie-Hellman groups
requested for each symmetric key size. New values from NIST
Special Publication 800-57 with the upper limit specified by (forwarded request 222365 from pcerny)