Kepler

I looked in to why KeplerGraphFrame has so much duplicated code
and it looks like Comad uses KeplerGraphFrameExtension

From the 2010-11-04 comment that added this class:

// "Added an extension for a different Drag and Drop behavior.           
    // Currently this is only activated in Comad.  Once an Actor is          
    // dragged from the Library over another actor on the canvas it          
    // will replace this actor and Ports are reconeected. Also               
    // Parameter values are used for parameters of the new actor if          
    // they have the same name.                                              
    //                                                                       
    // If an actor is dragged over a link this actor will be inserted        
    // there. Currently this only works in Comad, where all actors           
    // have an "input" and one "output" port."

The right thing is to add these extension points to the ptII repository
and remove the duplicated code.