7.6.0

1. Implement "tickz" draw option, used for color palette ticks
2. Implement skewness and kurtosis calculations for histogram stats box
3. Introduce "logv" draw option for TH3, configures logarithmic scale for box volume
4. Implement color palette drawing for TH3
5. Implement cutg draw option for TH2/TF2 surface plots
6. Implement TMath::Sq() function and several others like SinH, ASinH, ...
7. Implement histogram drawing build from TGraph2D using Delaunay interpolation
8. Provide preliminary TF3 support
9. Support TLinearGradient and TRadialGradient colors
10. Support LZMA decompression of ROOT files #272
11. Include ZSTD decompression to repository #274
12. Support opacity transfer function for TH3, see tutorials/gl/glvox2.C
13. Upgrade three.js r155 -> r158
14. Handle TCanvas::IsEdiatable() flag to disable some interactive features
15. Support PDF creation using jsPDF and svg2pdf.js - in browser and node.js
16. Implement custom fonts support in TWebCanvas
17. List of ROOT/JSON files on server with &dir=<path> URL parameter #283
18. Load TGaxis function from the file #282
19. Let display progress messages in modal element #285
20. Fix - do not add THStack and TMultiGraph to legend
21. Fix - correctly use margin in TPaveText class
22. Fix - correctly draw endcaps in legend errors
23. Fix - vertical position of up elements like {M}^{2} in TLatex
24. Fix - let draw THStack with diff binning hists
25. Fix - better tooltip name for the items
26. Fix - better logy scale selection