0.4 changes for FreeBSD 2.2.7-RELEASE

I had a few problems in aux/hf ...

In nf.l, I had to #include <netinet/in.h> before <arpa/inet.h> because
there's a prototype that uses 'struct in_addr' ... likewise in ef.l --
also around line 164 there's reference to a field ether_addr_octet that
seems to be just 'octet' now.

This looks like pretty old code, though.