Move copy rect handling to EncodeManager

No need to spread things out. Keep all of the handling in a single
place to make things clearer.
diff --git a/common/rfb/UpdateTracker.h b/common/rfb/UpdateTracker.h
index 8e96d55..8983b37 100644
--- a/common/rfb/UpdateTracker.h
+++ b/common/rfb/UpdateTracker.h
@@ -68,11 +68,9 @@
 
   class SimpleUpdateTracker : public UpdateTracker {
   public:
-    SimpleUpdateTracker(bool use_copyrect=true);
+    SimpleUpdateTracker();
     virtual ~SimpleUpdateTracker();
 
-    virtual void enable_copyrect(bool enable);
-
     virtual void add_changed(const Region &region);
     virtual void add_copied(const Region &dest, const Point &delta);
     virtual void subtract(const Region& region);
@@ -94,7 +92,6 @@
     Region changed;
     Region copied;
     Point copy_delta;
-    bool copy_enabled;
   };
 
 }