ENH: (Mv2) refined render tool-bar (added separators).

Code/Application/Mv2/mvdMainWindow.cxx

@@ -896,7 +896,13 @@ void
 MainWindow
 ::InitializeRenderToolBar()
 {
+  m_UI->m_RenderToolBar->addSeparator();
+
   {
+  m_UI->m_RenderToolBar->addWidget(
+    new QLabel( tr( "Ref.:" ) )
+  );
+
   QComboBox * comboBox =
     new QComboBox( m_UI->m_RenderToolBar );
 
@@ -908,6 +914,8 @@ MainWindow
   m_UI->m_RenderToolBar->addWidget( comboBox );
   }
 
+  m_UI->m_RenderToolBar->addSeparator();
+
   {
   m_UI->m_RenderToolBar->addWidget(
     new ShaderWidget( m_UI->m_RenderToolBar )