Main module headers are moved 1 level up

e.g. <opencv2/core/core.hpp> become <opencv2/core.hpp>

Also renamed <opencv2/core/opengl_interop.hpp> to <opencv2/core/opengl.hpp>

modules/contrib/include/opencv2/contrib.hpp

@@ -43,10 +43,10 @@
 #ifndef __OPENCV_CONTRIB_HPP__
 #define __OPENCV_CONTRIB_HPP__
 
-#include "opencv2/core/core.hpp"
-#include "opencv2/imgproc/imgproc.hpp"
-#include "opencv2/features2d/features2d.hpp"
-#include "opencv2/objdetect/objdetect.hpp"
+#include "opencv2/core.hpp"
+#include "opencv2/imgproc.hpp"
+#include "opencv2/features2d.hpp"
+#include "opencv2/objdetect.hpp"
 
 #ifdef __cplusplus
 
@@ -972,4 +972,3 @@ namespace cv
 #endif
 
 #endif
-

modules/contrib/include/opencv2/contrib/detection_based_tracker.hpp

@@ -2,8 +2,8 @@
 
 #if defined(__linux__) || defined(LINUX) || defined(__APPLE__) || defined(ANDROID)
 
-#include <opencv2/core/core.hpp>
-#include <opencv2/objdetect/objdetect.hpp>
+#include <opencv2/core.hpp>
+#include <opencv2/objdetect.hpp>
 
 #include <vector>
 

modules/contrib/include/opencv2/contrib/hybridtracker.hpp

@@ -43,12 +43,11 @@
 #ifndef __OPENCV_HYBRIDTRACKER_H_
 #define __OPENCV_HYBRIDTRACKER_H_
 
-#include "opencv2/core/core.hpp"
-#include "opencv2/core/operations.hpp"
-#include "opencv2/imgproc/imgproc.hpp"
-#include "opencv2/features2d/features2d.hpp"
+#include "opencv2/core.hpp"
+#include "opencv2/imgproc.hpp"
+#include "opencv2/features2d.hpp"
 #include "opencv2/video/tracking.hpp"
-#include "opencv2/ml/ml.hpp"
+#include "opencv2/ml.hpp"
 
 #ifdef __cplusplus
 

modules/contrib/include/opencv2/contrib/openfabmap.hpp

@@ -52,8 +52,8 @@
 #ifndef __OPENCV_OPENFABMAP_H_
 #define __OPENCV_OPENFABMAP_H_
 
-#include "opencv2/core/core.hpp"
-#include "opencv2/features2d/features2d.hpp"
+#include "opencv2/core.hpp"
+#include "opencv2/features2d.hpp"
 
 #include <vector>
 #include <list>

modules/contrib/include/opencv2/contrib/retina.hpp

@@ -72,7 +72,7 @@
  *      Author: Alexandre Benoit
  */
 
-#include "opencv2/core/core.hpp" // for all OpenCV core functionalities access, including cv::Exception support
+#include "opencv2/core.hpp" // for all OpenCV core functionalities access, including cv::Exception support
 #include <valarray>
 
 namespace cv