Modify the javadoc build process so it links against the JDK
javadoc.
--- a/build.xml
+++ b/build.xml
@@ -415,6 +415,7 @@
 	<include name="ds/common/BaseDataSource.java" />
 	<include name="xa/PGXADataSource.java" />
       </fileset>
+      <link href="/usr/share/doc/default-jdk-doc/api" />
     </javadoc>
   </target>