Build entity-view metamodel more intelligently

[Mobe91]

There are issues with complex entity view class hierarchies. E.g. mapped abstract methods defined in abstract superclasses of the entity-view base class might be overriden by equally-named methods coming from other super-interfaces. This dependes on the order in which the type hierarchy is traversed when the view type metamodel is built.
It would be nice to have a more intelligent process: Collect equally-named methods for the whole hierarchy and then choose the one with a mapping or report an error if conflicting mappings exist.