add command-line option --disable_retina for Mac

improve TimeSeries and Dof6ConstaintTutorial

examples/RenderingExamples/TimeSeriesCanvas.cpp

@@ -3,6 +3,7 @@
 #include "LinearMath/btAlignedObjectArray.h"
 #include "TimeSeriesFontData.h"
 #include "LinearMath/btVector3.h"
+#include <stdio.h>
 
 struct DataSource
 {
@@ -341,4 +342,4 @@ void TimeSeriesCanvas::nextTick()
 {
 	shift1PixelToLeft();
 	m_internalData->m_canvasInterface->refreshImageData(m_internalData->m_canvasIndex);
-}
+}