initdb: Select working dynamic shared memory implementation.

If POSIX shared memory is supported and works, we prefer it.
Otherwise, we prefer System V, except on Windows, where we use
the implementation specific to that platform.
Update regression tests for line type patch

Erroneously omitted in 261c7d4b653bc3e44c31fd456d94f292caa50d8f
Replace duplicate_oids with Perl implementation

It is more portable, more robust, and more readable.

From: Andrew Dunstan <andrew@dunslane.net>
Remove maintainer-check target, fold into normal build

make maintainer-check was obscure and rarely called in practice, and
many breakages were missed.  Fold everything that make maintainer-check
used to do into the normal build.  Specifically:

- Call duplicate_oids when genbki.pl is called.

- Check for tabs in SGML files when the documentation is built.

- Run msgfmt with the -c option during the regular build.  Add an
  additional configure check to see whether we are using the GNU
  version.  (make maintainer-check probably used to fail with non-GNU
  msgfmt.)

Keep maintainer-check as around as phony target for the time being in
case anyone is calling it.  But it won't do anything anymore.
doc: Handle additional character entities for SGML/XML conversion
doc: Fix table column number declaration
doc: Move check-tabs target into html target

The previous plan of having the check-tabs target a prerequisite of
"all" and "distprep" caused make distcheck to fail because make -q
distprep would never be satisfied.  Put check-tabs into the html target
instead, so it is only called when a build actually happens.
Rework SSL renegotiation code

The existing renegotiation code was home for several bugs: it might
erroneously report that renegotiation had failed; it might try to
execute another renegotiation while the previous one was pending; it
failed to terminate the connection if the renegotiation never actually
took place; if a renegotiation was started, the byte count was reset,
even if the renegotiation wasn't completed (this isn't good from a
security perspective because it means continuing to use a session that
should be considered compromised due to volume of data transferred.)

The new code is structured to avoid these pitfalls: renegotiation is
started a little earlier than the limit has expired; the handshake
sequence is retried until it has actually returned successfully, and no
more than that, but if it fails too many times, the connection is
closed.  The byte count is reset only when the renegotiation has
succeeded, and if the renegotiation byte count limit expires, the
connection is terminated.

This commit only touches the master branch, because some of the changes
are controversial.  If everything goes well, a back-patch might be
considered.

Per discussion started by message
20130710212017.GB4941@eldon.alvh.no-ip.org
Use $(PERL) to invoke duplicate_oids

Per buildfarm failure reported by smilodon
Fix several possibly non-portable gaffs in record_image_ops.

Sparc machines in the buildfarm were made happy by the previous
fix, but PowerPC machines still are still failing.  Hopefully this
will cure that.