Several exceptions added to the available FaceRecognizer classes and helper methods, so wrong input data is reported to the user. facerec_demo.cpp updated to latest cv::Algorithm changes and commented.

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

@@ -942,8 +942,6 @@ namespace cv
         // Deserializes this object from a given cv::FileStorage.
         virtual void load(const FileStorage& fs) = 0;
 
-        // Returns eigenvectors (if any)
-        virtual Mat eigenvectors() const { return Mat(); }
     };
 
     CV_EXPORTS Ptr<FaceRecognizer> createEigenFaceRecognizer(int num_components = 0);