Class which represents the relationship between a fieldelement which is seen as the foreign key field and a fieldelement which is seen as the primary key (identifying field) field. A FieldFieldRelationship is tied to the IdentifyingField (pkfield) specified and a normal relationship. If either of these two no longer exists or is no longer valid (field is no longer an identifying field for example) the FieldFieldRelationship instance will mark itself as deleted and will signal observers to threat it as such.

public class FieldRelationship : INotifyPropertyChanged, 
	INotifyAsChanged, INotifyAsRemoved, ISerializableToXml

Public Class FieldRelationship
	Implements INotifyPropertyChanged, INotifyAsChanged, INotifyAsRemoved, ISerializableToXml