Use entities to encode non-ASCII characters in SGML documentation

This has already been the case for the most part; just some cases had
slipped through.

doc/src/sgml/isn.sgml

@@ -377,7 +377,7 @@ SELECT isbn13(id) FROM test;
  <sect2>
   <title>Author</title>
   <para>
-   Germán Méndez Bravo (Kronuz), 2004 - 2006
+   Germ&aacute;n M&eacute;ndez Bravo (Kronuz), 2004 - 2006
   </para>
 
   <para>

doc/src/sgml/release-7.4.sgml

@@ -4143,7 +4143,7 @@ DROP SCHEMA information_schema CASCADE;
    </listitem>
 
    <listitem>
-    <para>Fix <literal>date_trunc('quarter', ...)</literal> (Böjthe Zoltán)</para>
+    <para>Fix <literal>date_trunc('quarter', ...)</literal> (B&ouml;jthe Zolt&aacute;n)</para>
     <para>
      Prior releases returned an incorrect value for this function call.
     </para>
@@ -4613,8 +4613,8 @@ DROP SCHEMA information_schema CASCADE;
    <listitem><para>Improve pgstattuple (Rod)</para></listitem>
    <listitem><para>Fix bug in <function>metaphone()</function> in fuzzystrmatch</para></listitem>
    <listitem><para>Improve adddepend (Rod)</para></listitem>
-   <listitem><para>Update spi/timetravel (Böjthe Zoltán)</para></listitem>
-   <listitem><para>Fix dbase <option>-s</> option and improve non-ASCII handling (Thomas Behr, Márcio Smiderle)</para></listitem>
+   <listitem><para>Update spi/timetravel (B&ouml;jthe Zolt&aacute;n)</para></listitem>
+   <listitem><para>Fix dbase <option>-s</> option and improve non-ASCII handling (Thomas Behr, M&aacute;rcio Smiderle)</para></listitem>
    <listitem><para>Remove array module because features now included by default (Joe)</para></listitem>
   </itemizedlist>
  </sect3>

doc/src/sgml/release-8.4.sgml

@@ -5467,7 +5467,7 @@ WITH w AS (SELECT * FROM foo) SELECT * FROM w, bar ... FOR UPDATE
        <para>
         Allow <application>pg_dump</>, <application>pg_dumpall</>, and
         <application>pg_restore</> to use a specified role (Benedek
-        L<EFBFBD>szl<EFBFBD>)
+        L&aacute;szl&oacute;)
        </para>
       </listitem>