shift renderer prototype to new node structure

app/node/output.h

@@ -61,14 +61,11 @@ public:
    * In many cases for efficiency, the Node can also ignore this request if it knows the output data will not change
    * (i.e. if the time has not changed from the last Process()).
    */
-  virtual const QVariant& get_value(const rational &time);
+  virtual QVariant get_value(const rational &time);
 
 private:
   DataType data_type_;
 
-  QVariant value_;
-
-  rational time_;
 };
 
 #endif // NODEOUTPUT_H