update Datum to act as conjunction/empty when desirable
Update to reflect changes made for multiple children
Add method to datum to show if it is empty
Modifications for better conjunction handling
Merge branch 'changeConjunctions'

* changeConjunctions:
  Modifications for better conjunction handling
  Add method to datum to show if it is empty
  Update to reflect changes made for multiple children
  update Datum to act as conjunction/empty when desirable