Import OpenSSH-6.1p1.

Import OpenSSH-6.1p1.

Features:

 * ssh-keygen(1): Add optional checkpoints for moduli screening
 * ssh-add(1): new -k option to load plain keys (skipping certificates)
 * sshd(8): Add wildcard support to PermitOpen, allowing things like
   "PermitOpen localhost:*".  bz #1857
 * ssh(1): support for cancelling local and remote port forwards via the
   multiplex socket. Use ssh -O cancel -L xx:xx:xx -R yy:yy:yy user@host"
   to request the cancellation of the specified forwardings
 * support cancellation of local/dynamic forwardings from ~C commandline
 * sshd(8): This release turns on pre-auth sandboxing sshd by default for
   new installs, by setting UsePrivilegeSeparation=sandbox in sshd_config.
 * ssh-keygen(1): Add options to specify starting line number and number of
   lines to process when screening moduli candidates, allowing processing
   of different parts of a candidate moduli file in parallel
 * sshd(8): The Match directive now supports matching on the local (listen)
   address and port upon which the incoming connection was received via
   LocalAddress and LocalPort clauses.
 * sshd(8): Extend sshd_config Match directive to allow setting AcceptEnv
   and {Allow,Deny}{Users,Groups}
 * Add support for RFC6594 SSHFP DNS records for ECDSA key types. bz#1978
 * ssh-keygen(1): Allow conversion of RSA1 keys to public PEM and PKCS8
 * sshd(8): Allow the sshd_config PermitOpen directive to accept "none" as
   an argument to refuse all port-forwarding requests.
 * sshd(8): Support "none" as an argument for AuthorizedPrincipalsFile
 * ssh-keyscan(1): Look for ECDSA keys by default. bz#1971
 * sshd(8): Add "VersionAddendum" to sshd_config to allow server operators
   to append some arbitrary text to the server SSH protocol banner.

Bugfixes:

 * ssh(1): ensure that $DISPLAY contains only valid characters before
   using it to extract xauth data so that it can't be used to play local
   shell metacharacter games.
 * ssh(1): unbreak remote portforwarding with dynamic allocated listen ports
 * scp(1): uppress adding '--' to remote commandlines when the first
   argument does not start with '-'. saves breakage on some
   difficult-to-upgrade embedded/router platforms
 * ssh(1)/sshd(8): fix typo in IPQoS parsing: there is no "AF14" class,
   but there is an "AF21" class
 * ssh(1)/sshd(8): do not permit SSH2_MSG_SERVICE_REQUEST/ACCEPT during
   rekeying
 * ssh(1): skip attempting to create ~/.ssh when -F is passed
 * sshd(8): unbreak stdio forwarding when ControlPersist is in use; bz#1943
 * sshd(1): send tty break to pty master instead of (probably already
   closed) slave side; bz#1859
 * sftp(1): silence error spam for "ls */foo" in directory with files;
   bz#1683
 * Fixed a number of memory and file descriptor leaks
 * ssh(1)/sshd(8): Don't spin in accept() in situations of file
   descriptor exhaustion. Instead back off for a while.
 * ssh(1)/sshd(8): Remove hmac-sha2-256-96 and hmac-sha2-512-96 MACs as
   they were removed from the specification. bz#2023,
 * sshd(8): Handle long comments in config files better. bz#2025
 * ssh(1): Delay setting tty_flag so RequestTTY options are correctly
   picked up. bz#1995
 * sshd(8): Fix handling of /etc/nologin incorrectly being applied to root
   on platforms that use login_cap.