Fixing a problem with deserialization.

The changing of the XStream version solves the problem of deserialization reported in #628.

Closes #628.
I thought this, but when a serialization is recursive, the change is directly in the `Serializee`, because the method `from` returns a `Serializee` as we can see in this code: https://github.com/caelum/vraptor4/blob/master/vraptor-core/src/main/java/br/com/caelum/vraptor/serialization/xstream/XStreamXMLSerialization.java#L81