(#695) Unintentional picking fixed.

Fixed in viewer, keeping the concept of the navigation policies to not flag the
the events as handled.
Made this clearer by adding an interface to turn event consumption on or off on the
navigation policies.

ApplicationCode/UserInterface/RiuViewer.cpp

@@ -228,6 +228,13 @@ void RiuViewer::mouseReleaseEvent(QMouseEvent* event)
 
     if (event->button() == Qt::LeftButton)
     {
+        QPoint diffPoint = event->pos() - m_lastMousePressPosition;
+        if (diffPoint.manhattanLength() > 3)
+        {
+            // We are possibly in navigation mode, only clean press event will launch
+            return;
+        }
+
         if (!m_infoLabelOverlayArea.isNull())
         {
             if (m_infoLabelOverlayArea.contains(event->x(), event->y()))
@@ -239,7 +246,9 @@ void RiuViewer::mouseReleaseEvent(QMouseEvent* event)
         }
 
         m_viewerCommands->handlePickAction(event->x(), event->y(), event->modifiers());
+
         return;
+
     }
     else if (event->button() == Qt::RightButton)
     {