Ability to store generic entity information

[theJenix]

Sometimes, I may want to store a reference that could be one of a couple different entities. Java provides limited support for this beyond exposing an Object as the field type. ORMada could look at this object (appropriately tagged) and store a reference to the class of the reference. That way, it could pull back and recreate any arbitrary entity, and it would be up to the consumer to figure out how to interpret it.