Doc: update or remove dead external links.

Re-point comp.ai.genetic FAQ link to a more stable address.

Remove stale links to AIX documentation; we don't really need to
tell AIX users how to use their systems.

Remove stale links to HP documentation about SSL.  We've had to
update those twice before, making it increasingly obvious that
HP does not intend them to be stable landing points.  They're
not particularly authoritative, either.  (This change effectively
reverts bbd3bdba3.)

Daniel Gustafsson and Álvaro Herrera, per a gripe from
Kyotaro Horiguchi.  Back-patch, since these links are
just as dead in the back branches.

Discussion: https://postgr.es/m/20200709.161226.204639179120026914.horikyota.ntt@gmail.com

doc/src/sgml/geqo.sgml

@@ -271,7 +271,7 @@
    <itemizedlist>
     <listitem>
      <para>
-      <ulink url="http://www.aip.de/~ast/EvolCompFAQ/">
+      <ulink url="http://www.faqs.org/faqs/ai-faq/genetic/part1/">
       The Hitch-Hiker's Guide to Evolutionary Computation</ulink>, (FAQ for <ulink
       url="news://comp.ai.genetic"></ulink>)
      </para>

doc/src/sgml/installation.sgml

@@ -2242,62 +2242,6 @@ ERROR:  could not load library "/opt/dbs/pgsql/lib/plperl.so": Bad address
      out-of-memory kill is configurable on a system- or process-wide
      basis if this becomes a problem.
     </para>
-
-    <bibliography>
-     <title>References and Resources</title>
-
-     <biblioentry>
-      <biblioset relation="article">
-       <title><ulink url="http://publib.boulder.ibm.com/infocenter/pseries/topic/com.ibm.aix.doc/aixprggd/genprogc/lrg_prg_support.htm">Large Program Support</ulink></title>
-      </biblioset>
-      <biblioset relation="book">
-       <title>AIX Documentation: General Programming Concepts: Writing and Debugging Programs</title>
-      </biblioset>
-     </biblioentry>
-
-     <biblioentry>
-      <biblioset relation="article">
-       <title><ulink url="http://publib.boulder.ibm.com/infocenter/pseries/topic/com.ibm.aix.doc/aixprggd/genprogc/address_space.htm">Program Address Space Overview</ulink></title>
-      </biblioset>
-      <biblioset relation="book">
-       <title>AIX Documentation: General Programming Concepts: Writing and Debugging Programs</title>
-      </biblioset>
-     </biblioentry>
-
-     <biblioentry>
-      <biblioset relation="article">
-       <title><ulink url="http://publib.boulder.ibm.com/infocenter/pseries/v5r3/topic/com.ibm.aix.doc/aixbman/prftungd/resmgmt2.htm">Performance Overview of the Virtual Memory Manager (VMM)</ulink></title>
-      </biblioset>
-      <biblioset relation="book">
-       <title>AIX Documentation: Performance Management Guide</title>
-      </biblioset>
-     </biblioentry>
-
-     <biblioentry>
-      <biblioset relation="article">
-       <title><ulink url="http://publib.boulder.ibm.com/infocenter/pseries/v5r3/topic/com.ibm.aix.doc/aixbman/prftungd/memperf7.htm">Page Space Allocation</ulink></title>
-      </biblioset>
-      <biblioset relation="book">
-       <title>AIX Documentation: Performance Management Guide</title>
-      </biblioset>
-     </biblioentry>
-
-     <biblioentry>
-      <biblioset relation="article">
-       <title><ulink url="http://publib.boulder.ibm.com/infocenter/pseries/v5r3/topic/com.ibm.aix.doc/aixbman/prftungd/memperf6.htm">Paging-space thresholds tuning</ulink></title>
-      </biblioset>
-      <biblioset relation="book">
-       <title>AIX Documentation: Performance Management Guide</title>
-      </biblioset>
-     </biblioentry>
-
-     <biblioentry>
-       <title><ulink url="http://www.redbooks.ibm.com/abstracts/sg245674.html?Open">Developing and Porting C and C++ Applications on AIX</ulink></title>
-       <publisher>
-        <publishername>IBM Redbook</publishername>
-       </publisher>
-     </biblioentry>
-    </bibliography>
    </sect3>
   </sect2>
 

doc/src/sgml/libpq.sgml

@@ -7916,9 +7916,6 @@ ldap://ldap.acme.com/cn=dbserver,cn=hosts?pgconnectinfo?base?(objectclass=*)
    that the <literal>libssl</literal> and/or <literal>libcrypto</literal> libraries
    have been initialized by your application, so that
    <application>libpq</application> will not also initialize those libraries.
-   See <ulink
-   url="http://h41379.www4.hpe.com/doc/83final/ba554_90007/ch04.html"></ulink>
-   for details on the SSL API.
   </para>
 
   <para>

doc/src/sgml/runtime.sgml

@@ -2257,9 +2257,6 @@ pg_dumpall -p 5432 | psql -d postgres -p 5433
    intermediate certificates were created with <literal>v3_ca</literal>
    extensions).  Certificate Revocation List (CRL) entries are also
    checked if the parameter <xref linkend="guc-ssl-crl-file"/> is set.
-   (See <ulink
-   url="http://h41379.www4.hpe.com/doc/83final/ba554_90007/ch04s02.html"></ulink>
-   for diagrams showing SSL certificate usage.)
   </para>
 
   <para>