DatabaseStorageControllerNG accesses field properties hardcoded in following methods:
In all this locations
->value is used to either read or write a field property.
This is ugly because there's no rule that defines that a field has to have a
value field property.
entity as properties.
EntityReferenceItem has some mapping in its getter / setter methods to deal with
However, we really should provide a sane way to define what properties have to be handled by the storage controler.
Open question: Is there the posibility that e.g.
EntityReferenceItem can define more than one property to be stored / read?