Copy from master : add missing math core tests
from master: add FindBin in TKDTreeBinning plus add test program. Copy from master CMake file for tests in mathcore
Fix the AD GoF test for a bug in integer overflows. Use also now tables from R code from kSamples package to compute the p value. This fixes ROOT-6666
Update reference values, by computing expected values using R.
skip test if math more is not present