BSD lib/setkey.h and lib/sysio.h #include fixes. OpenBSD's flex needs -o param without space. V6ONLY for SK_IP fix.
Add code for manipulation with TCP-MD5 keys in the IPsec SA/SP database at FreeBSD systems. Now, BGP MD5 authentication (RFC 2385) keys are handled automatically on both Linux and FreeBSD. Based on patches from Pavel Tvrdik.