major refactoring of the ifcp dissector.

major refactoring of the ifcp dissector.

remove the port preference setting and replace it with strong heuristics instead
(attempt but fail to set a conversation dissector when the heuristics and the dissection match)

use tcp_dissect_pdus() for reassembly and pdu tracking and get rid of the try-to-step-through-the-pdu-to-find-where-the-next-pdu-starts thing.

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@17804 f5534014-38df-0310-8fa8-9805f1628bb7