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>

Added workaround for Nvidia: take into account that 3-channel vector type takes 4*elem_size in local memory.

new hysteresis

delete whitespaces

fix problem with mad24

Dynamic work group size

dynamic work group size

Fix problem with warnings

Fix some problems with border

Another one fix

Delete trailing whitespaces

some changes

fix problem with warning

Apart from not displaying the table, it breaks the doc build of https://github.com/Itseez/opencv_contrib/pull/70.

Switch branch to master.
New IPP func - ippiCopy
Conv: YUV2GRAY_420