----------------------------
- [instancer] Set RIBBI bits in head and OS/2 table when cutting instances and the
subfamily nameID=2 contains strings like 'Italic' or 'Bold' (2673).
- [otTraverse] Addded module containing methods for traversing trees of otData tables
(2660).
- [otTables] Made DeltaSetIndexMap TTX dump less verbose by omitting no-op entries
(2660).
- [colorLib.builder] Added option to disable PaintColrLayers's reuse of layers from
LayerList (2660).
- [varLib] Added support for merging multiple master COLRv1 tables into a variable
COLR table (2660, 2328). Base color glyphs of same name in different masters must have
identical paint graph structure (incl. number of layers, palette indices, number
of color line stops, corresponding paint formats at each level of the graph),
but can differ in the variable fields (e.g. PaintSolid.Alpha). PaintVar* tables
are produced when this happens and a VarStore/DeltaSetIndexMap is added to the
variable COLR table. It is possible for non-default masters to be 'sparse', i.e.
omit some of the color glyphs present in the default master.
- [feaLib] Let the Parser set nameIDs 1 through 6 that were previously reserved (2675).
- [varLib.varStore] Support NO_VARIATION_INDEX in optimizer and instancer.
- [feaLib] Show all missing glyphs at once at end of parsing (2665).
- [varLib.iup] Rewrite force-set conditions and limit DP loopback length (2651).
For Noto Sans, IUP time drops from 23s down to 9s, with only a slight size increase
in the final font. This basically turns the algorithm from O(n^3) into O(n).
- [featureVars] Report about missing glyphs in substitution rules (2654).
- [mutator/instancer] Added CLI flag to --no-recalc-timestamp (2649).
- [SVG] Allow individual SVG documents in SVG OT table to be compressed on uncompressed,
and remember that when roundtripping to/from ttx. The SVG.docList is now a list
of SVGDocument namedtuple-like dataclass containing an extra ``compressed`` field,
and no longer a bare 3-tuple (2645).
- [designspaceLib] Check for descriptor types with hasattr() to allow custom classes
that don't inherit the default descriptors (2634).
- [subset] Enable sharing across subtables of extension lookups for harfbuzz packing
(2626). Updated how table packing falls back to fontTools from harfbuzz (2668).
- [subset] Updated default feature tags following current Harfbuzz (2637).
- [svgLib] Fixed regex for real number to support e.g. 1e-4 in addition to 1.0e-4.
Support parsing negative rx, ry on arc commands (2596, 2611).
- [subset] Fixed subsetting SinglePosFormat2 when ValueFormat=0 (2603).