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

Pull in all the OpenSSH bits that we'd previously left out because we
didn't use them. This will make future merges from the vendor tree much
easier.

Approved by: re (gjb)

Since we automatically set svn:eol-style on new files (including files
added during a vendor import), set it on the entire dist tree.

Vendor import of OpenSSH 4.6p1 for posterity's sake