- Fixed bug whereby OS/2 codepage range bits weren't correctly computed

  for variable fonts (all unset except fallback bit 0).
  This happened when a designspace contained a `<variable-font>` element
  with a `'public.fontInfo'` lib key that did *not* explicitly override `openTypeOS2CodePageRanges` (#897).

Fixed typos in USE_SCRIPTS list of ISO script tags for USE-enabled sc…

…ripts: Bhaiksuki -> "Bhks" (not "Nhks"), N'ko -> "Nkoo" (not "Nko ").

They should now get 'dist' feature instead of 'kern', and 'abvm' and
'blwm' instead of 'mark', like the other USE_SCRIPTS (#896).

- [postProcessor] fontTools.varLib.cff.convertCFFtoCFF2 is deprecated (…

…#882)

- [outlineCompiler] Warn when building COLRv0 if gid1 is not blank (#886)
- [instantiator] Use designspace.findDefault() the first time designspace.default is checked (#887)
- [markFeatureWriter] Fix ligatures with unnumbered contextual anchors having their mark attachment dropped (#890)
- [markFeatureWriter] Support contextual mark2mark anchors (#895)
- [markFeatureWriter] Drop “ambiguously connected” info message (#892)
- [removeOverlaps] Capture TypeError and ValueError that pathops and booleanOperations might raise (#492)
- [doc] Document lib keys modifying ufo2ft's behavior (#286)

- [featureWriters] Support insert marker in the middle of a feature b…

…lock (#873)

- [cursFeatureWriter] Respect direction suffix when setting lookupflag (#876)

- Rewrite old kern writer to pull in some changes made in the newer o…

…ne (#870)

- markFeatureWriter: Support contextual anchors (#869)
- markFeatureWriter: Support contextual ligature anchors (#871)

- [featureWriters] Ensure CursFeatureWriter comes first, before kerni…

…ng mark feature writers; in some non-HarfBuzz implementations the GPOS lookup order matters (#864).

- [kernFeatureWriter] Ignore zero-valued class-class kerning pairs when generating variable kern feature as they are no-op (#866).
- Take discrete axes into account when checking for feature compatibility across masters (#867).

- cursFeatureWriter: Remove stray print()

- kernFeatureWriter: Support sparse masters

- cursFeatureWriter: Support multiple entry/exit anchor pairs

- Removed unnecessary assertions that may sometime trigger an Asserti…

…onError while setting a glyph's right margin in dottedCircle filter (#849).

- Fix variable anchors when DesignSpace source specifies a layer (#842).

- Update the old kernFeatureWriter2.py to be able to output variable FEA for use compiling features once per VF (#841, #845).