Postfix now normalizes IP addresses received with XCLIENT, XFORWARD,
or with the HaProxy protocol, for consistency with direct connections
to Postfix. This may change the appearance of logging, and the way
that check_client_access will match subnets of an IPv6 address.

Documentation: tlsext_padding is not a tls_ssl_options
feature. File: proto/postconf.proto.

Portability: to avoid a compile-time error on Solaris, added
"#undef sun" to util/unix_dgram_connect.c.

Bugfix (introduced: Postfix 2.3): a censoring filter broke
multiline Milter responses for header/body events. Problem
report by Andreas Thienemann. Files: util/printable.c,
util/stringops.h, smtpd/smtpd.c.

Bugfix (introduced: Postfix 3.3): "smtp_mx_address_limit = 0"
no longer meant 'unlimited'. Problem report by Luc Pardon.
File: smtp/smtp_addr.c.

Cleanup: normalize the IP address string forms received with
XCLIENT, XFORWARD, and HaProxy, for consistency with address
information for direct connections to Postfix, and add unit
tests. This casefolds and removes redundant nulls from the
string representation of an IPv6 address, normalizes the
"IPv6:" address prefix of RFC 2821 IPv6 address forms, and
converts IPv4 address octets with leading zeros (octal form)
into decimal form. Files: global/haproxy.c,
global/normalize_mailhost_addr.[hc], smtpd/smtpd.c.

Incompatibility: this may change the appearance of logging,
and the way that check_client_access will match subnets of
an IPv6 address.