finished conforming renderers to new node structure

Stateless node system is done! Functionality is about equal to the functionality
in master meaning this is ready for merging.

app/render/backend/videorenderbackend.cpp

@@ -47,10 +47,10 @@ void VideoRenderBackend::InvalidateCache(const rational &start_range, const rati
   rational start_range_adj = qMax(rational(0), start_range);
   rational end_range_adj = qMin(SequenceLength(), end_range);
 
-  /*qDebug() << "Cache invalidated between"
+  qDebug() << "Cache invalidated between"
            << start_range_adj.toDouble()
            << "and"
-           << end_range_adj.toDouble();*/
+           << end_range_adj.toDouble();
 
   // Snap start_range to timebase
   double start_range_dbl = start_range_adj.toDouble();