Code from the hack-session known as the IETF (and a
bit of debugging afterwards):

• Fix protection code for notification generation.
• Decouple associd from vtag
• Allow vtags to have less strigent requirements in non-uniqueness. o don't pre-hash them when you issue one in a cookie. o Allow duplicates and use addresses and ports to discriminate amongst the duplicates during lookup.
• Add support for the NAT draft draft-ietf-behave-sctpnat-00, this is still experimental and needs more extensive testing with the Jason Butt ipfw changes.
• Support for the SENDER_DRY event to get DTLS in OpenSSL working with a set of patches from Michael Tuexen (hopefully heading to OpenSSL soon).
• Update the support of SCTP-AUTH by Peter Lei.
• Use macros for refcounting.
• Fix MTU for UDP encapsulation.
• Fix reporting back of unsent data.
• Update assoc send counter handling to be consistent with endpoint sent counter.
• Fix a bug in PR-SCTP.
• Fix so we only send another FWD-TSN when a SACK arrives IF and only if the adv-peer-ack point progressed. However we still make sure a timer is running if we do have an adv_peer_ack point.
• Fix PR-SCTP bug where chunks were retransmitted if they are sent unreliable but not abandoned yet.

With the help of: Michael Teuxen and Peter Lei :-)
MFC after: 4 weeks