X collapse pdeengine/pderunner/kjcengine

X   remove 'extends' from kjcengine, make an instance of Main
X     may need to subclass at.dms.kjc.Main to override the exit()
X   make pdeengine a class
X   remove pderunner, collapse into pdeengine

app/PdeBase.java

@@ -400,11 +400,13 @@ public class PdeBase implements ActionListener {
 
 
   // does this do anything useful?
+  /*
   public void destroy() {
     if (editor != null) {
       editor.terminate();
     }
   }
+  */
 
   /*
   public void paint(Graphics g) {