TODO: Make nosse ver faster than Sobel
      Make sse ver faster than Sobel for BORDER_REPLICATE

TODO: HAL-accelerated code

Some code style corrections;

Removed IPP port for tiny arithm.cpp functions

Additional warnings fix on various platforms.

Build without OPENCL and GCC warnings fixed

Fixed warnings, trailing spaces and removed unused secure_cpy.

IPP code refactored.

IPP code path  implemented as separate static functions to simplify future work with IPP code and make it more readable.

The inner loop of the backward scan got the wrong initial "a".

improvements in Haar CascadeClassifier: 1) use CV_32S instead of CV_32F for the integral of squares (which is more accurate and more efficient); 2) skip the window if its contrast is too low

Signed-off-by: NZhigang Gong <zhigang.gong@intel.com>

int pix_per_thr = l_counter / LOCAL_TOTAL + ((lid < mod) ? 1 : 0);
The pix_per_thr * LOCAL_TOTAL may be larger than l_counter.
Thus the index of l_stack may be negative which may cause serious
problems. Let's skip the loop when we get negative index and we need
to add back the lcounter to keep its balance and avoid potential
negative counter.
Signed-off-by: NZhigang Gong <zhigang.gong@intel.com>