* use __GNUC_MINOR__ in correct place to check the version of GCC
  * check processor support of FP16 at run time
  * check compiler support of FP16 and pass correct compiler option
  * rely on ENABLE_AVX on gcc since AVX is generated when mf16c is passed
  * guard correctly using ifdef in case of various configuration
  * use v_float16x4 correctly by including the right header file

  * use v_float16x4 (universal intrinsic) instead of raw SSE/NEON implementation
  * define v_load_f16/v_store_f16 since v_load can't be distinguished when short pointer passed
  * brush up implementation on old compiler (guard correctly)
  * add test for v_load_f16 and round trip conversion of v_float16x4
  * fix conversion error

  * DRY
  * switch to Cv32suf and remove fp32Int32
  * add Cv16suf

  * avoid using vld1_f16 and vst1_f16 on gcc 4 series (Ubuntu 14.04)
  * guard correctly with #if
  * use static inline

  * raise an error when wrong bit depth passed
  * raise an build error when wrong depth is specified for cvtScaleHalf_
  * remove unnecessary safe check in cvtScaleHalf_
  * use intrinsic instead of direct pointer access
  * update the explanation

  * make sure that CV_FP16 has the correct meaning
  * check FP16 feature correctly

  * integrate HW version and SW version to same function

  * check compiler more strictly
  * use gcc version of fp16 conversion if it's possible (gcc 4.7 and later)
  * use current SW implementation in other cases

  * remove useHW option
  * update test

  * check compiler support
  * check HW support before executing
  * add test doing round trip conversion from / to FP32
  * treat array correctly if size is not multiple of 4
  * add declaration to prevent warning
  * make it possible to enable fp16 on 32bit ARM
  * let the conversion possible on non-supported HW, too.
  * add test using both HW and SW implementation

fixes #5876

- added new functions from core module: split, merge, add, sub, mul, div, ...
- added function replacement mechanism
- added example of HAL replacement library

IPP_VERSION_MAJOR * 100 + IPP_VERSION_MINOR*10 + IPP_VERSION_UPDATE
to manage changes between updates more easily.

IPP_DISABLE_BLOCK was added to ease tracking of disabled IPP functions;

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.