MFC r271970

ipv6 address for test.hosts.dots in wrong byte order.

Obtained from:	ipfilter CVS repo (r1.11), netbsd CVS repo (r1.5)
MFC r271971

Fix ipfilter bug #553 gethost needs to zero entire IP address structure.

Obtained from:	ipfilter CVS repo (r1.11)
MFC r271972

Fix ipfilter bug #536 ipnat can try to print rule as dstlist incorrectly.

Obtained from:	ipfilter CVS repo (r1.14), netbsd CVS repo (r1.3)
MFC r271974

ipfilter bug #551 ipf.conf address structure not properly zero filled.

Obtained from:	ipfilter CVS repo (r1.37), netbsd CVS repo (r1.3)
MFC r271977

3561691 gethost never returns an ipv6 address

Obtained from:	ipfilter CVS repo (r1.34), netbsd CVS repo (r1.4)
MFC r271978

ipfilter bug #552 destination port not zero after parsing nat rule.

Obtained from:	netbsd CVS repo (r1.4), ipfilter CVS repo (r1.38)
MFC r271980

Check for NULL before de-refencing; in particular sel is assigned to NULL,
in the default case, and then couple of lines down we do sel->

Obtained from:	NetBSD CVS repo (r1.5)
MFC r272052

ipfilter bug #558 add in some missing frag table function comments.

Obtained from:	ipfilter CVS repo (r1.36)
MFC r272551

ipfiler bug #550 filter rule list corrupted with inserted rules

Obtained from:	ipfilter CVS repo (r1.128); NetBSD CVS repo (r1.15)
MFC r272552

ipfilter bug #554 Determining why a ipf rule matches is hard -- replace
ipfilter rule compare with new ipf_rule_compare() function.

Obtained from:	ipfilter CVS rep (r1.129)
MFC r272553

ipfilter bug #538 ipf_p_dns_del should return void

Obtained from:	ipfilter cvs repo (r1.8)
MFC r272554

ipfilter bug #534 destination list hashing not endian neutral

Obtained from:	ipfilter CVS repo (r1.26), NetBSD CVS repo (r1.8)
MFC r272555

ipfilter bug #537 NAT rules with sticky have incorrect hostmap IP address.
This fixes when an IP address mapping is put in the hostmap table for
sticky NAT rules, it ends up having the wrong byte order.

Obtained from:	ipfilter CVS repo (r1.102), NetBSD CVS repo (r1.12)
MFC r272571:
Remove unused MC_ALIGN macro as suggested by Robert.
MFC r272750:
Ensure that the number of stream reported in srs_number_streams is
consistent with the amount of data provided in the SCTP_RESET_STREAMS
socket option.
Thanks to Peter Bostroem from Google for drawing my attention to
this part of the code.
MFC r272751:
Ensure that the list of streams sent in a stream reset parameter fits
in an mbuf-cluster.
Thanks to Peter Bostroem for drawing my attention to this part of the code.
MFC r272841:
Ensure that the flags field of sctp_tmit_chunks is initialized.
Thanks to Peter Bostroem from Google for reporting the issue.