patch to send incoming key to AuthorizedKeysCommand via stdin

[Scott Duckworth]

On Sun, Mar 23, 2014 at 5:27 PM, Scott Duckworth <sduckwo at clemson.edu>
wrote:
> I can work on creating a patch against master and post it to the bug that
you referenced in your first response to me.

I've attached the patch against cvs to
https://bugzilla.mindrot.org/show_bug.cgi?id=2081#c5.  The patch also
includes documentation about the new feature to the sshd_config man page.