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/PdeEngine.java

@@ -1,5 +1,21 @@
-public interface PdeEngine {
-  public void start() throws PdeException;
-  public void stop();
-  public void close();
+public class PdeEngine {
+  PdeEditor editor;
+
+  public PdeEngine(PdeEditor editor) {
+    this.editor = editor;
+  }
+
+  // implemented by subclasses
+
+  public void start() throws PdeException {
+  }
+
+  public void front() {
+  }
+
+  public void stop() {
+  }
+
+  public void close() {
+  }
 }