Ostap:

• Move 2D fitting machinery into separate module Fit2D
  • reshufflle 2D-utilities between modules
• create new 3D-fitting machinery (in the module Fig3D)
  • create H3D_dset & H3D_pdf
• add method minmax for VE
• add possibility to only part of iterations for reweighting (useful for study of systematic uncertainties)
• PidCalib2: add new options, useful for tests with new samples -s/--samples -t/--testpatterns reshullfe a bit the code to use new options
  • change the output printout
  • add check for ""triviality" of probe_(Brunel_)sWeight