* block packets that fail to create state table entries
* only allow non-fragmented packets to influence whether or not a logged
packet is the same as the one logged before.
* correct the ICMP packet checksum fixing up when processing ICMP errors for NAT
* implement a maximum for the number of entries in the NAT table (NAT_TABLE_MAX
and ipf_nattable_max)
* frsynclist() wasn't paying attention to all the places where interface
names are, like it should.
* fix comparing ICMP packets with established TCP state where only 8 bytes
of header are returned in the ICMP error.
MFC after: 1 week
