Merge pull request #550 from ISISComputingGroup/Ticket2563_synoptics_drag_and_drop

Add data to transfer as dummy string.

Author: Tom-Willemsen

base/uk.ac.stfc.isis.ibex.ui.synoptic.editor/src/uk/ac/stfc/isis/ibex/ui/synoptic/editor/instrument/InstrumentTreeView.java

@@ -132,6 +132,11 @@ public void createControls(Composite parent) {
         		    public void dragStart(DragSourceEvent event) {
                         currentDragSource = synopticViewModel.getSelectedComponents();
         		    }
+                    
+                    @Override
+                    public void dragSetData(DragSourceEvent event) {
+                    	event.data = "Data";
+                    }
 
         		    @Override
         		    public void dragFinished(DragSourceEvent event) {