• update to 2.11.7
• use target helpers

ChangeLog:
20150903
Workaround: disable DNSSEC support for AIX 7x and earlier.
The AIX 6/7 resolver(5) API defines RES_USE_DNSSEC without
defining the "ad" bit. Viktor Dukhovni. Files: makedefs,
proto/INSTALL.html, dns/dns.h.

20150923
Bugfix (introduced: 20120531-617): the Postfix SMTP server
used a larger-than-1 VSTREAM buffer to read the HAProxy
connection hand-off information. This broke TLS wrappermode,
as the TLS helo packet would end up in the plaintext VSTREAM
buffer. Reported by Lukas Erlacher. File: smtpd/smtpd_haproxy.c.

20150924
Bugfix (introduced: 20090216-24): incorrect postmulti error
message. Reported by Patrik Koetter. Fix by Viktor Dukhovni.
File: postmulti/postmulti.c.

Workaround: don't create a new instance when the template
main.cf and master.cf files are missing, as happens on
Debian-like systems. Viktor Dukhovni. File: conf/postmulti-script.

20150925
Bugfix (introduced: 19970309, fixed 20150421 in development
release): reset errno before calling readdir(), in order
to distinguish between an end-of-directory and an error
condition. File: scandir.c.

20150930
Bugfix (introduced: 20040124): Milter client panic while
adding a header, because the PREPEND action used the same
output function for header_checks and body_checks. Viktor
Dukhovni and Wietse. File: cleanup/cleanup_message.c.

Bugfix (introduced: 20031128): xtext_unquote() did not
propagate error reports from xtext_unquote_append(), causing
the decoder to return partial ouput, instead of rejecting
malformed input. Fix by Krzysztof Wojta. File: global/xtext.c.