- check if compiler is Intel compiler
 - remove not referenced variables

added v_reduce_sum4() universal intrinsic; corrected number of threads in cv::getNumThreads() in the case of GCD

 - fix the define condition based on the comment

It used for Matlab binding only

There is no cast to wide integer type:
    std::numeric_limits<ST>::max() * std::numeric_limits<ST>::max()