Privacy list should implement Cacheable

Privacy list now implements Serializable but the follow error might occur. Instead we should implement the Cacheable interface.

2006.06.21 09:22:44 [org.jivesoftware.util.Cache.calculateSize(Cache.java:545)]
java.io.NotSerializableException: org.jivesoftware.wildfire.roster.RosterItem$SubType
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1075)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1369)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1341)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1284)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:291)
at java.util.ArrayList.writeObject(ArrayList.java:569)
at sun.reflect.GeneratedMethodAccessor34.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25 )
at java.lang.reflect.Method.invoke(Method.java:585)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:890)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1333)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1284)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1369)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1341)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1284)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:291)
at org.jivesoftware.util.Cache.calculateSize(Cache.java:541)
at org.jivesoftware.util.Cache.put(Cache.java:120)
at org.jivesoftware.wildfire.privacy.PrivacyListManager.getDefaultPrivacyList(PrivacyLi stManager.java:108)