Add javadoc-afu target to build.xml
diff --git a/build.xml b/build.xml
index 3a7f287..06850a2 100644
--- a/build.xml
+++ b/build.xml
@@ -42,6 +42,10 @@
         <ant dir="${afu}" target="jarfile"/>
     </target>
 
+    <target name="javadoc-afu">
+        <ant dir="${afu}" target="javadoc"/>
+    </target>
+
     <target name="test-afu">
         <ant dir="${afu}" target="run-tests"/>
     </target>