preliminary stuff to make a Dashboard
introduced a Dashboard class that contains a FlowPane object,
in alternative to implementing the Dashboard as an extension of FlowPane
made DashboardEventHandler an inner class of StructureView, so that its
handle method can access the structureView to which the dashboard
belongs
implemented label() in DomainView; renamed members to viewParent and
scrren
in StructureView
the buttons in the Dashpane are assigned to private variables, etc
sortEventHanlder()
failed attempt to extend an inner class in a separate file.
The compiler said: couldn't find an enclosing object due to some
intermediate
constructor
removed the failed extended class
created (non-nested) abstract class Dashboard
created package jfxnav.view and moved 4 classes into it
moved inner class to a separate file: compile errors present
fixed errors
created DomainDashboard and moved sortButton into it (it's not activated
now)
refactored in StructureView: 
ViewHandle -> Handle; 
body to bodyScreen; 
dashboard -> dashboardScreen 
ViewBody -> BodyScreen
Storing a reference to the parent Navigator in StructureViews;
Since Structure's contain a method navigatorView() 
to create a StructureView, lots of interfaces had to be updated
renamed navigatorView(Navigator) to makeView(Navigator)
removed Navigator argument from signature of activate;
noticed run time error when launching the Table View
removed bizarre repetition of argument in FlowPaneDashboard constructor
introduced factory method makeDashboard(StructureView) in StructureView;
Created the Domain implementation (see DomainView, DomainDashboard)
moved core code out of makeCreateButton, into method makeView;
removed the useless Navigator argument from it