Adding an export for HOGDetector compatibility.

An SVM train with HOG could export a single vector for HOGDetector.

modules/ml/include/opencv2/ml.hpp

@@ -518,6 +518,9 @@ public:
     virtual CvSVMParams get_params() const { return params; };
     CV_WRAP virtual void clear();
 
+    // return a single vector for HOG detector.
+    virtual void get_svm_detector( std::vector< float > & detector ) const;
+
     static CvParamGrid get_default_grid( int param_id );
 
     virtual void write( CvFileStorage* storage, const char* name ) const;