Move non-CV functionality from core.hpp to separate utility.hpp header

samples/cpp/freak_demo.cpp

@@ -38,11 +38,12 @@
 #include <string>
 #include <vector>
 
-#include <opencv2/core/core.hpp>
-#include <opencv2/highgui/highgui.hpp>
-#include <opencv2/features2d/features2d.hpp>
-#include <opencv2/nonfree/features2d.hpp>
-#include <opencv2/legacy/legacy.hpp>
+#include <opencv2/core.hpp>
+#include "opencv2/core/utility.hpp"
+#include <opencv2/highgui.hpp>
+#include <opencv2/features2d.hpp>
+#include <opencv2/nonfree.hpp>
+#include <opencv2/legacy.hpp>
 
 using namespace cv;