various node UI improvements

app/node/processor/renderer/renderer.cpp

@@ -20,8 +20,7 @@
 
 #include "renderer.h"
 
-RendererProcessor::RendererProcessor(QObject *parent) :
-  Node(parent),
+RendererProcessor::RendererProcessor() :
   started_(false)
 {
 

app/node/processor/renderer/renderer.h

@@ -34,7 +34,7 @@ public:
    * Constructing a Renderer object will not start any threads/backend on its own. Use Start() to do this and Stop()
    * when the Renderer is about to be destroyed.
    */
-  RendererProcessor(QObject* parent = nullptr);
+  RendererProcessor();
 
   virtual QString Name() override;
   virtual QString Category() override;