NLGInputView for RelEx

The new view for RelEx output is the NLGInputView. This view is designed, as its name implies, to be used as input for NLGen2. It is largely based on the SimpleView. The first difference is that the entity arguments to predicates are replaced by indices. An entity is either an object or event and they are identified by the binary predicates that always contain entities. The _subj and _obj predicates are examples as are almost all prepositional predicates. The second difference is that explicit lemma predicates are added to the list in order to associate a word form with the logical index. This output view does not ensure that the lemma is in its root form. That task will be performed by some of the early processing of NLGen2 in PVM formation.