MFH (r314306,r314720): Upgrade OpenSSH to 7.4p1.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Upgrade to OpenSSH 6.7p1, retaining libwrap support (which has been removed
upstream) and a number of security fixes which we had already backported.

MFC after: 1 week

Upgrade to OpenSSH 6.6p1.

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)

Vendor import of OpenSSH 6.3p1

Vendor import of OpenSSH 5.6p1

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

svn:keywords is not appropriate for vendor trees.

Properly flatten openssh/dist.

Revert part of 180714 - the intent was to flatten dist, not to nuke it.

Vendor import of OpenSSH 4.0p1.

Vendor import of OpenSSH 3.9p1.

Vendor import of OpenSSH 3.8.1p1.