Add Triangle thresholding algorithm

Add Triangle method for automatic threshold computation next to the existing
Otsu's method. Triangle deals better with images whose histogram does not
contain dominant peak.

See paper Zack GW, Rogers WE, Latt SA.: Automatic measurement of sister
chromatid exchange frequency. J Histochem Cytochem. 1977 Jul;25(7):741-53.
Add test for calib3d function decomposeProjectionMatrix(...)
update IPPICV package
IPPICV: disable NormDiff_L1_16s_C1R for IPP/ICV 8.2/8.2.1
IPPICV: disable boxFilter 16SC1/16UC1 (performance)
Make Otsu and Triangle algorithms mutually exclusive

Make Otsu and Triangle algorithms mutually exclusive in cv::threshold code.

Signed-off-by: Miroslav Benes <mbenes@suse.cz>
ocl: change processing of OpenCL failures

disable "unwanted" messages
Merge pull request #3360 from mirab:threshold_triangle
Merge pull request #3391 from alalek:ocl_failure_messages
Merge pull request #3372 from pokeefe:add-test-for-projection-decomposition
Removed incorrect using of rootn() and powr() in ocl_pow
Merge pull request #3396 from akarsakov:ocl_pow_fix
Merge pull request #3138 from alalek:icv_update