* kame/sys/netinet6/natpt_*.c: - Does not process a IPv4 multicast packet.   This packet is processed with code in ip_input(). - Drop fragmented ICMPv4 packet.   We can not re-calculate ICMP checksum because translator does not   re-assemble this fragmented packet so we can not get an ICMP length   information. - Fix a problem that data transfer fails when connect from v6   client to v4 FTP server, and FTP server does not use 20 as   source port number in data transfer with non-passive mode. - Change the expiration time of translation slot entry.
* kame/sys/netinet6/natpt_*.c:
- Does not process a IPv4 multicast packet.
  This packet is processed with code in ip_input().
- Drop fragmented ICMPv4 packet.
  We can not re-calculate ICMP checksum because translator does not
  re-assemble this fragmented packet so we can not get an ICMP length
  information.
- Fix a problem that data transfer fails when connect from v6
  client to v4 FTP server, and FTP server does not use 20 as
  source port number in data transfer with non-passive mode.
- Change the expiration time of translation slot entry.

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