Bugfix(introduced: 20091121): with the introduction of
sender_dependent_default_transport_maps, the SMTP daemon
was not updated. This resulted in false rejects with
sender-dependent "error" transports. Based on a fix by
Russell Yanofsky.  Files: global/resolve_clnt.c,
global/resolve_clnt.h, smtpd/smtpd_check.c, smtpd/smtpd_check.h,
smtpd/smtpd_milter.c, smtpd/smtpd_resolve.c, smtpd/smtpd_resolve.h.

Refinements to the 20160618 fix. For more consistent results
with sender address validation, use the recipient address
(if available) as the sender-dependent address resolver
context.  For better caching, pass sender context with all
attempts to resolve an email address.  File: smtpd/smtpd.c,
smtpd/smtpd_check.c, smtpd/smtpd_milter.c.

Cleanup: the Postfix SMTP server now passes network address
and port information to the Cyrus SASL library. Build with
``make makefiles "CCARGS=$CCARGS -DNO_IP_CYRUS_SASL_AUTH"''
for backwards compatibility. Files: makedefs,
smtpd/smtpd_sasl_glue.c, xsasl/xsasl.h, xsasl/xsasl_cyrus_server.c,
xsasl/xsasl_server.c.
Cleanup: dnsblog manpage. File: dnsblog/dnsblog.c.