created wrappers for new NPP functions

removed void integral(const GpuMat& src, GpuMat& sum, GpuMat& sqsum, Stream& stream) - it fails with NPP_NOT_IMPLEMENTED error
updated docs, accuracy and performance tests

modules/gpu/perf/perf_main.cpp

@@ -11,7 +11,7 @@ int main(int argc, char **argv)
 
 #else
 
-int main(int argc, char** argv)
+int main()
 {
     printf("OpenCV was built without CUDA support\n");
     return 0;