v1.4.4.0: 1. Redesign all *shelve-like data bases,

1. Redesign all *shelve-like data bases:
   • add abstract base class
   • implement concrete databases :
     • zipshelve (ZIP/GZIP compression )
     • bz2shelve (BZIP2 compression) in terms of base class
     • lzshelve (LZMA-compression) only for python3
2. impove timing functions
3. improve TTree.the_variables
4. selector via frames: change order of variables in snapshot
5. improve statistics for selectors
6. improve a bit printout for TTree/TChain (sorted, type,...)
7. improve a bit printout for DataFrame (sorted)
8. generate temporary column names for DataFrame using hash instead of random
   • it allows better debugging (reproducible)
9. re-enable security key for paralell python servers
10. Update all tree-collection utilities
    • Files
    • Data
    • Data2
    • DataAndLuimi
11. Add colorization to progress bars
12. fix (hope) segfaults for adding new branch to tuple
13. Improve colorization
14. make optional use of terminaltables package
15. add local function to format tables
16. improve printout of trees and datasets
17. more improvements in tables&colorization
18. improve reweighting machinery
19. add 2D and 3D moments for the historgams
20. improve 2D histos comparison functions
21. improve progress bar
22. fix addition of new brnaches to TTree/TChain and whole IFuncTree machinery
23. change the names for example-tests
24. add script to check the dependensies
25. one more attempt to fix the crash for FuncTH1
    • add_branches - Notifier is not invoked... Invoke it explicitely!
    • FuncTH1::Notify : reset/delete formula instead of Notify...
    • fixes in Notifier
    • few more fixes
    • add a test for add_branches
26. make a try to polish a bit the Doxygen/Sphinx machinery
27. PDF.draw_nll : fix bug for the weighted datasets
28. Update test_tools_reweight2.py
29. Add Ostap::Math::ChebyshevApproximation
30. bug fix in add_branch
31. extend PDF.nll to accept all keywords
32. unify PDF.nll keywords with pdf.fitTo keywords
33. tmva & tmva/chopping: fix problem with non-deleted temporary files/directories
34. cleanup : add concept of "local" trash, to be deleted when CleanUp instance is deleted
35. mp_pathos & parallel/task: improve the output of the final statistics, add total time and CPU gain due to paralellization
36. minor fix in TGraphAsymmErrors.transform
37. add_branch/add_new_branch
    • extend current functionlaity allowing to add several branches at once
38. Add "clone" methods for all io-databases
39. Add dump_root module/utility/recipe to allow reading of databases
    created with "old" ROOT versions, with old version of streamers
40. add/extend math-function for graphs
41. remove drawing artifacts for PDF.draw_nll method
42. Add ROOT.TGraph.remove method
43. Improve ROOT.TGraph.filter method
44. Add plotting options for combined_background, combined_signal and combined_components
45. Extend the signature for Ostap::Math::gauss_pdf/gauss_cdf
46. Add PSSmear_pdf - smeared version for PhaseSpace-based PDFs
47. Add signals & backgrounds keywords for Fit1D-constructor
48. Add 'args' argument to draw-functions
49. Add possibility for prefilter of data for TMVA/chopping.
50. Allow TMVA/chopping tools to process RooFit datasets: (converted internally to TTree)
51. optimize evaluation of polynomials in Ostap::Math
52. Add Ostap::Math::Clenshaw::term - evaluate the N-th term of the recursive sequence
53. Add Ostap::Math::barrier_factor - evaluation of Blatt-Weisskopf angular momentum
    centrifugal form factors for arbitrary angular momenta
54. Fix but in VE.purity : Thanks to Alexey Dziuba
55. Improve configuration of canvas&styles
56. Few fixes in Dalitz, epsecially for drawing it
57. Add DalitzIntegrator for relatively efficient integration over Dalitz plot
58. Add true analytical 3-body phase space
59. Add check for duplicated variable/pdfs names
60. Add ProgressBar action for DataFrame, now one can display the progress bar
    during the processing of large frames.
61. Add context manager to remove/add certain topics to RooMsgService