use the new-style headers in the samples to improve OpenCV build time.

samples/cpp/segment_objects.cpp

@@ -1,5 +1,6 @@
-#include "cvaux.h"
-#include "highgui.h"
+#include <opencv2/imgproc/imgproc.hpp>
+#include <opencv2/highgui/highgui.hpp>
+#include <opencv2/video/background_segm.hpp>
 #include <stdio.h>
 #include <string>