State table reorganisation
Timeline

Initially conceived			~ May 2004 (after pf2k4)
Interface abstraction cleanup		2005-05-21	1.489
Alternate Routing Tables		2006-07-06	1.513
Basic split of state struct		2007-05-29	1.534
Fix interface-bound states		2007-06-21	1.546
Core state table change		2008-05-29	1.576/1.577
Link inbound/outbound states		2008-06-11	1.590
Link states to PCBs			2008-07-03	1.604
Remove scrub rules, add match		2009-04-06	1.640
Remove NAT/RDR/BINAT rules	2009-09-01	1.658