Factory method for a default XML properties instance. Application and domain class loaders will
be initialised to the one used to load this class. The properties instance returned will be a
CastorProperties with a XMLProperties and a CoreProperties instance as parents. The
CastorProperties holding user specific properties is the only one that can be modified by put()
and remove() methods. XMLProperties and CoreProperties are responsible to deliver Castor's
default values if they have not been overwritten by the user.