duplicated ipf sources between dist/ipf and sys/dist/ipf?

[Christoph Badura <bad%bsd.de@localhost>]

Does anyone know why the following files exist with small differences
both in src/dist/ipf and src/sys/dist/ipf?
Most of the differences are that the files in src/dist/ipf still use
caddr_t.

ip_htable.c
ip_htable.h
ip_irc_pxy.c
ip_lookup.c
ip_lookup.h
ip_pool.c
ip_pool.h
ip_pptp_pxy.c
ip_rpcb_pxy.c
ip_scan.c
ip_scan.h
ip_sync.c
ip_sync.h

--chris