Modify the javadoc build process so it links against the JDK
javadoc.
Index: libpostgresql-jdbc-java/build.xml
===================================================================
--- libpostgresql-jdbc-java.orig/build.xml	2012-08-17 21:12:35.493845322 +0100
+++ libpostgresql-jdbc-java/build.xml	2012-08-17 21:17:24.083845400 +0100
@@ -451,6 +451,7 @@
 	<include name="ds/common/BaseDataSource.java" />
 	<include name="xa/PGXADataSource.java" />
       </fileset>
+      <link href="/usr/share/doc/default-jdk-doc/api" />
     </javadoc>
   </target>