7.9.0

1. New draw options:
   • 'pol' and 'arr_colz' draw option for TH2
   • 'col7' uses bar offset and width for TH2
   • 'cont5' for TGraph2D using Delaunay algorithm
   • 'chord' drawing of TH2 implements zooming
   • 'box1' for TH3 with negative bins
   • 'same' option for first histogram on pad, draw without creating TFrame
   • 'rangleNN' for TGraphPolargram, also support fAxisAngle member
   • 'N' and 'O' for TGraphPolargram for angle coordinate systems
   • 'arc' for TPave and derived classes
   • 'allbins' for histograms to display underflow/overflow bins
   • Poisson errors for TH1/TH2, https://root-forum.cern.ch/t/62335/
   • test fSumw2 when detect empty TH2 bin, sync with root-project/root#17948
2. New supported classes:
   • TF12 - projection of TF2
   • TLink and TButton, used in TInspectCanvas
3. New partameters in TTree::Draw:
   • '>>elist' to request entries matching cut conditions
   • 'elist' to specify entries for processing
   • 'nmatch' to process exactly the specified number of entries, break processing afterwards
   • 'staged' algorithm to first select entries and then process only these entries
4. New settings parameters:
   • settings.FilesTimeout global timeout for file reading operations
   • settings.FilesRemap fallback address for http server, used for root.cern
   • settings.TreeReadBunchSize bunch read size for TTree processing
   • settings.UserSelect to set 'user-select: none' style in drawings to exclude text selection
5. Context menus:
   • all TPave-derived classes
   • in 'chord' drawings of TH2
   • editing histogram and graph title
6. Fixes:
   • match histogram title drawing with native ROOT implementation
   • float to string conversion when 'g' is specified
   • handle TPave NDC position also when fInit is not set
   • properly handle image sizes in svg2pdf
   • drawing TPaveText with zero text size
   • correct axis range in TScatter drawing
   • use draw option also for graph drawing in TTree::Draw
7. Internals:
   • upgrade three.js r168 -> r174
   • use private members and methods
   • use WeakRef class for cross-referencing of painters
   • use negative indexes in arrays and Strings
   • remove support of qt5 webengine, only qt6web can be used