Clean up and update comments in function to handle move to new cart (Move To Duplicate Cart)
Add parameter for backupRequest to indicate that the request object will be deleted.
Overload call to backupRequest to handle single parameter case that will default to deleted=False.
Update backupRequest comments and variable names.
Update cancelEdits to handle the case where a request item was deleted.
Add method to DataModel to clear the modded Requests and backed Requests lists.
Add call in cancelEdits of Requests to call clearBackupRequests() after UI has been updated.
Move removeLeafnonValueItems to end of cancelEdits in order to get rid of any empty carts after everything has been moved back to the way it was.
Update the removeLeafNonValueItems to be a recursive call that removes the empty carts from the list using the itterator's remove method.
Add commented out stub into ReqTreeCell factory to handle mouseClick events and display cart number in the info text area.
Add listener to tree view to listen for changes to the selection model.
Update drag and drop to permit moving multiple selected request items to new cart.
Update method of drag & drop for multiple selections to use a snapshot of the selected items.  This prevents the changing selection model (due to the moved items) of causing pre-mature termination.  Basically, it makes sure all the items get moved.
Move around functions and update comments.
Add function to get fresh cart number given old cart number.  This function will simply update the date aspect of the cart number hash while preserving the requestor part of the hash.
Update drag and drop to empty cart to backup the request and then get a fresh cart number.  Make the program behavior to match the user intention of moving the entry to a new cart.
Update selection change listener set on the Tree View to handle nulls is the returned selectedItems List.
Remove the background color change of commit edits.  It causes lines to show in the tree view.
Add listener to the data model is busy property for the request operations.
Add panel overlay that can be set to visible to grey out the request view and intercept all the mouse events.
Add fxml and css required to implement the busy overlay panel.
Move post transactional functionality from commitEdits button action handler to Listener that reacts to changes in appropriate isBusy property of the data model.