Removed helper functions from header.

Updated module license text.

Author: terfendail

modules/xfeatures2d/include/opencv2/xfeatures2d.hpp

@@ -279,12 +279,6 @@ CV_EXPORTS void FASTForPointSet( InputArray image, CV_IN_OUT std::vector<KeyPoin
                       int threshold, bool nonmaxSuppression=true, int type=FastFeatureDetector::TYPE_9_16);
 
 
-void makeOffsets(int pixel[25], int row_stride, int patternSize);
-
-template<int patternSize>
-int cornerScore(const uchar* ptr, const int pixel[], int threshold);
-
-
 //! @}
 
 }