Big sweep over the IPFIREWALL and IPACCT code.

Close the ip-fragment hole.
Waste less memory.
Rewrite to contemporary more readable style.
Kill separate IPACCT facility, use "accept" rules in IPFIREWALL.
Filter incoming >and< outgoing packets.
Replace "policy" by sticky "deny all" rule.
Rules have numbers used for ordering and deletion.
Remove "rerorder" code entirely.
Count packet & bytecount matches for rules.

Code in -current & -stable is now the same.