external/openssh: update to 6.8p1.

In preparation for some updates to external/openssh to make it work with
BoringSSL, this change updates the code to a recent version. The current
version (5.9p1) is coming up on four years old now.

  * Confirmed that f5c67b478bef9992de9e9ec91ce10af4f6205e0d matches
    OpenSSH 5.9p1 exactly (save for the removal of the scard
    subdirectory).

  * Downloaded openssh-6.8p1.tar.gz (SHA256:
    3ff64ce73ee124480b5bf767b9830d7d3c03bbcb6abe716b78f0192c37ce160e)
    and verified with PGP signature. (I've verified Damien's key in
    person previously.)

  * Applied changes between f5c67b478bef9992de9e9ec91ce10af4f6205e0d and
    OpenSSH 5.9p1 to 6.8p1 and updated the build as best I can. The
    ugliest change is probably the duplication of umac.c to umac128.c
    because Android conditionally compiles that file twice. See the
    comment in those files.

Change-Id: I63cb07a8118afb5a377f116087a0882914cea486
diff --git a/ssh-keysign.8 b/ssh-keysign.8
index 5e09e02..69d0829 100644
--- a/ssh-keysign.8
+++ b/ssh-keysign.8
@@ -1,4 +1,4 @@
-.\" $OpenBSD: ssh-keysign.8,v 1.12 2010/08/31 11:54:45 djm Exp $
+.\" $OpenBSD: ssh-keysign.8,v 1.14 2013/12/07 11:58:46 naddy Exp $
 .\"
 .\" Copyright (c) 2002 Markus Friedl.  All rights reserved.
 .\"
@@ -22,7 +22,7 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: August 31 2010 $
+.Dd $Mdocdate: December 7 2013 $
 .Dt SSH-KEYSIGN 8
 .Os
 .Sh NAME
@@ -63,6 +63,7 @@
 .Pp
 .It Pa /etc/ssh/ssh_host_dsa_key
 .It Pa /etc/ssh/ssh_host_ecdsa_key
+.It Pa /etc/ssh/ssh_host_ed25519_key
 .It Pa /etc/ssh/ssh_host_rsa_key
 These files contain the private parts of the host keys used to
 generate the digital signature.
@@ -74,6 +75,7 @@
 .Pp
 .It Pa /etc/ssh/ssh_host_dsa_key-cert.pub
 .It Pa /etc/ssh/ssh_host_ecdsa_key-cert.pub
+.It Pa /etc/ssh/ssh_host_ed25519_key-cert.pub
 .It Pa /etc/ssh/ssh_host_rsa_key-cert.pub
 If these files exist they are assumed to contain public certificate
 information corresponding with the private keys above.
@@ -88,4 +90,4 @@
 first appeared in
 .Ox 3.2 .
 .Sh AUTHORS
-.An Markus Friedl Aq markus@openbsd.org
+.An Markus Friedl Aq Mt markus@openbsd.org