Huge packet filter update

Jan Lentfer has updated pf (and pflogd and ftp-proxy) in DragonFly to match what was in OpenBSD 4.1.  Why this intermediate step?  pf went through a lot of changes after OpenBSD 4.1, so this was easier than jumping right to the current version – which he plans next.

In any case, this was a huge and difficult job, with somewhere around 10,000 lines of code added, and very useful for DragonFly.  Jan also managed to keep the DragonFly-specific features working, where “no state” is the default, along with features like fairq.