MFH (r265214, r294333, r294407, r294467): misc prop fixes
MFH (r285975, r287143): register mergeinfo for security fixes
MFH (r294497, r294498, r295139): internal documentation
MFH (r294328): upgrade to openssh 6.7p1, re-add libwrap
MFH (r294332): upgrade to openssh 6.8p1
MFH (r294367): update pam_ssh for api changes
MFH (r294909): switch usedns back on
MFH (r294336): upgrade to openssh 6.9p1
MFH (r294495): re-enable dsa keys
MFH (r294464): upgrade to openssh 7.0p1
MFH (r294496): upgrade to openssh 7.1p2

Approved by: re (gjb)
Relnotes: yes

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Upgrade to OpenSSH 5.4p1.

MFC after: 1 month

Vendor import of OpenSSH 5.4p1