message: core(stat): stat.cpp minor refactoring
  remove unused code
  added: #if CV_ENABLE_UNROLLED in Hamming's functions
diff: namespace cv
  {
  -template<typename T> static inline Scalar rawToScalar(const T& v)
  -{
  - Scalar s;
  - typedef typename DataType<T>::channel_type T1;
  - int i, n = DataType<T>::channels;
  - for( i = 0; i < n; i++ )
  - s.val[i] = ((T1*)&v)[i];
  - return s;
  -}
  -
  /****************************************************************************************\
  * sum *
  \****************************************************************************************/
  @@ -4344,12 +4334,13 @@ int normHamming(const uchar* a, int n)
  result += v_reduce_sum(t);
  }
  #endif // CV_SIMD128
  -
  +#if CV_ENABLE_UNROLLED
  for(; i <= n - 4; i += 4)
  {
  result += popCountTable[a[i]] + popCountTable[a[i+1]] +
  popCountTable[a[i+2]] + popCountTable[a[i+3]];
  }
  +#endif
  for(; i < n; i++)
  {
  result += popCountTable[a[i]];
  @@ -4415,12 +4406,13 @@ int normHamming(const uchar* a, const uchar* b, int n)
  result += v_reduce_sum(t);
  }
  #endif // CV_SIMD128
  -
  +#if CV_ENABLE_UNROLLED
  for(; i <= n - 4; i += 4)
  {
  result += popCountTable[a[i] ^ b[i]] + popCountTable[a[i+1] ^ b[i+1]] +
  popCountTable[a[i+2] ^ b[i+2]] + popCountTable[a[i+3] ^ b[i+3]];
  }
  +#endif
  for(; i < n; i++)
  {
  result += popCountTable[a[i] ^ b[i]];
  