Any OpenJPA property can be configured for each individual slice. The property name
     is of the form openjpa.slice.[Logical slice name].[OpenJPA Property Name].
     For example, openjpa.slice.One.ConnectionURL where One
     is the logical slice name and ConnectionURL is an OpenJPA property
     name. 
     
     If a property is not configured for a specific slice, then the value for
     the property equals to the corresponding openjpa.* property.