Add a listing of our SQLSTATE error codes to the documentation.

Link to it from some appropriate places.

doc/src/sgml/ecpg.sgml

 <!--
-$Header: /cvsroot/pgsql/doc/src/sgml/ecpg.sgml,v 1.52 2003/09/20 20:12:04 tgl Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/ecpg.sgml,v 1.53 2003/10/17 18:57:00 tgl Exp $
 -->
 
 <chapter id="ecpg">
@@ -1151,13 +1151,13 @@ struct
     two characters indicate the general class of the condition, the
     last three characters indicate a subclass of the general
     condition.  A successful state is indicated by the code
-    <literal>00000</literal>.  Further information about the codes can
-    be found XXX.  The <literal>SQLSTATE</literal> codes are for the
-    most part defined in the SQL standard.  The
+    <literal>00000</literal>.  The <literal>SQLSTATE</literal> codes are for
+    the most part defined in the SQL standard.  The
     <productname>PostgreSQL</productname> server natively supports
     <literal>SQLSTATE</literal> error codes; therefore a high degree
     of consistency can be achieved by using this error code scheme
-    throughout all applications.
+    throughout all applications.  For further information see
+    <xref linkend="errcodes-appendix">.
    </para>
 
    <para>
@@ -1178,7 +1178,8 @@ struct
     <literal>SQLSTATE</literal> is also listed.  There is, however, no
     one-to-one or one-to-many mapping between the two schemes (indeed
     it is many-to-many), so you should consult the global
-    <literal>SQLSTATE</literal> listing in XXX in each case.
+    <literal>SQLSTATE</literal> listing in <xref linkend="errcodes-appendix">
+    in each case.
    </para>
 
    <para>

doc/src/sgml/filelist.sgml

-<!-- $Header: /cvsroot/pgsql/doc/src/sgml/filelist.sgml,v 1.30 2003/09/01 23:01:49 petere Exp $ -->
+<!-- $Header: /cvsroot/pgsql/doc/src/sgml/filelist.sgml,v 1.31 2003/10/17 18:57:01 tgl Exp $ -->
 
 <!entity history    SYSTEM "history.sgml">
 <!entity info       SYSTEM "info.sgml">
@@ -23,6 +23,7 @@
 <!entity datetime   SYSTEM "datetime.sgml">
 <!entity ddl        SYSTEM "ddl.sgml">
 <!entity dml        SYSTEM "dml.sgml">
+<!entity errcodes   SYSTEM "errcodes.sgml">
 <!entity features   SYSTEM "features.sgml">
 <!entity func       SYSTEM "func.sgml">
 <!entity indices    SYSTEM "indices.sgml">

doc/src/sgml/libpq.sgml

 <!--
-$Header: /cvsroot/pgsql/doc/src/sgml/libpq.sgml,v 1.139 2003/10/04 21:05:20 tgl Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/libpq.sgml,v 1.140 2003/10/17 18:57:01 tgl Exp $
 -->
 
  <chapter id="libpq">
@@ -1332,8 +1332,8 @@ localized translation of one of these.  Always present.
 </term>
 <listitem>
 <para>
-The SQLSTATE code for the error (a 5-character string following SQL
-spec conventions).  Not localizable.  Always present.
+The SQLSTATE code for the error (see <xref linkend="errcodes-appendix">).
+Not localizable.  Always present.
 </para>
 </listitem>
 </varlistentry>

doc/src/sgml/postgres.sgml

 <!--
-$Header: /cvsroot/pgsql/doc/src/sgml/postgres.sgml,v 1.56 2003/09/12 22:17:23 tgl Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/postgres.sgml,v 1.57 2003/10/17 18:57:01 tgl Exp $
 -->
 
 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook V3.1//EN" [
@@ -244,6 +244,7 @@ $Header: /cvsroot/pgsql/doc/src/sgml/postgres.sgml,v 1.56 2003/09/12 22:17:23 tg
  <part id="appendixes">
   <title>Appendixes</title>
 
+  &errcodes;
   &datetime;
   &keywords;
   &features;

doc/src/sgml/protocol.sgml

-<!-- $Header: /cvsroot/pgsql/doc/src/sgml/protocol.sgml,v 1.45 2003/09/20 20:12:05 tgl Exp $ -->
+<!-- $Header: /cvsroot/pgsql/doc/src/sgml/protocol.sgml,v 1.46 2003/10/17 18:57:01 tgl Exp $ -->
 
 <chapter id="protocol">
  <title>Frontend/Backend Protocol</title>
@@ -3833,9 +3833,8 @@ message.
 </Term>
 <ListItem>
 <Para>
-        Code: the SQLSTATE code for the error (a 5-character
-        string following SQL spec conventions).  Not localizable.
-        Always present.
+        Code: the SQLSTATE code for the error (see <xref
+	linkend="errcodes-appendix">).  Not localizable.  Always present.
 </Para>
 </ListItem>
 </VarListEntry>