IPP can be switched on and off on runtime;

Optional implementation collector was added (switched off by default in CMake). Gathers data of implementation used in functions and report this info through performance TS;

TS modifications for implementations control;

Added OCL performance test for YUV2RGB_IYUV, YUV2GRAY_420, RGB2YUV_IYUV, YUV2RGB_YUY2, YUV2GRAY_YUY2 color conversion modes

According to opencl 1.2 spec 6.1.5:
    For arguments to a __kernel function declared to be a pointer to a
    data type, the OpenCL compiler can assume that the pointee is always
    appropriately aligned as required by the data type. The behavior of
    an unaligned load or store is undefined, except for the
    vloadn, vload_halfn, vstoren, and vstore_halfn functions defined in
    section 6.12.7.

Original code read data of type T from address not aligned by multiple
of sizeof(T), so the result is incorrect. With this patch, the cases
./opencv_perf_imgproc
--gtest_filter=OCL_ImgSize_TmplSize_Method_MatType_MatchTemplate.MatchTemplate/*
could work well with beignet 0.9.3.
Signed-off-by: Chuanbo Weng <chuanbo.weng@intel.com>