* kame/sys/netinet6/natpt_tslot.c (checkTracerouteReturn): - Translate incoming IPv4 ICMP_UNREACH packet when this   ICMP_UNREACH returns from IPv4 network, and it is a error   return for IPv6 host.	 Only return of traceroute was a   target until now.
* kame/sys/netinet6/natpt_tslot.c (checkTracerouteReturn):
- Translate incoming IPv4 ICMP_UNREACH packet when this
  ICMP_UNREACH returns from IPv4 network, and it is a error
  return for IPv6 host.	 Only return of traceroute was a
  target until now.

* kame/sys/netinet6/natpt_{dispatch.c,tslot.c,var.h}
- Changed routine name as follows due to modification
  mentioned above.
    checkTracerouteReturn() -> checkIncomingICMP()

MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame