Improve description of loread/lowrite.

Patch by me, reviewed by Tatsuo Ishii.

doc/src/sgml/lobj.sgml

@@ -527,14 +527,10 @@ int lo_unlink(PGconn *conn, Oid lobjId);
 
   <para>
    There are server-side functions callable from SQL that correspond to
-   each of the client-side functions described above(please note
+   each of the client-side functions described above; indeed, for the
-   that the server side function
+   most part the client-side functions are simply interfaces to the
-   for <function>lo_read</function> is <function>loread</function> and
+   equivalent server-side functions.  The ones that are actually useful
-   the server side function for <function>lo_write</function>
+   to call via SQL commands are
-   is <function>lowrite</function>); indeed, for the most part the
-   client-side functions are simply interfaces to the equivalent
-   server-side functions.  The ones that are actually useful to call
-   via SQL commands are
    <function>lo_creat</function><indexterm><primary>lo_creat</></>,
    <function>lo_create</function><indexterm><primary>lo_create</></>,
    <function>lo_unlink</function><indexterm><primary>lo_unlink</></>,
@@ -576,6 +572,14 @@ SELECT lo_export(image.raster, '/tmp/motd') FROM image
     The client-side functions do not require superuser privilege.
   </para>
 
+  <para>
+    The functionality of <function>lo_read</function> and
+    <function>lo_write</function> is also available via server-side calls,
+    but the names of the server-side functions differ from the client side
+    interfaces in that they do not contain underscores.  You must call
+    these functions as <function>loread</> and <function>lowrite</>.
+  </para>
+
 </sect1>
 
 <sect1 id="lo-examplesect">