In the CriteriaQueryTranslator, we process the path given by
a SubCriteria object looking for the entity name for the property. If
the SubCriteria was mistakenly created on a component type, we will exit
the loop using the owning entity, and will eventually end up failing
(throwing an exception) trying to lookup up the restricted property
against the entity, instead of against the component. Fix this by
throwing a more informative exception, and modify the documentation to
be explicit about how to do this properly.
