The Drop''''''Target is only needed if the Cytoscape''''''Editor is loaded, so we can redesign Phoebe''''''Canvas to only add a drop target to itself if the Cytoscape''''''Editor is active.  Phoebe''''''Canvas is going to need to change, anyway, since it currently is based upon Picolo's P''''''Canvas class.  Under the new renderer, Picolo will be going away, so this modularity with respect to drop targets can be designed into the new incarnation of Phoebe''''''Canvas.