Merging master to filter_avx2, and resolving conflicts

diff --cc modules/imgproc/src/filter.cpp
index 2b9e925,10d8315..ff7c1e4
--- 1/modules/imgproc/src/filter.cpp
--- 2/modules/imgproc/src/filter.cpp
+++ b/modules/imgproc/src/filter.cpp
@@@ -1361,8 -1360,7 +1361,8 @@@ struct RowVec_32
      {
          kernel = _kernel;
          haveSSE = checkHardwareSupport(CV_CPU_SSE);
- #if defined USE_IPP_SEP_FILTERS && IPP_DISABLE_BLOCK
 +        haveAVX2 = checkHardwareSupport(CV_CPU_AVX2);
+ #if defined USE_IPP_SEP_FILTERS
          bufsz = -1;
  #endif
      }
@@@ -1432,8 -1408,7 +1432,8 @@@ if ( haveAVX2 
  
      Mat kernel;
      bool haveSSE;
- #if defined USE_IPP_SEP_FILTERS && IPP_DISABLE_BLOCK
 +    bool haveAVX2;
+ #if defined USE_IPP_SEP_FILTERS
  private:
      mutable int bufsz;
      int ippiOperator(const uchar* _src, uchar* _dst, int width, int cn) const