tooling: upgrade libs, rename VF fext otf -> ttf, add STAT table patch

- upgrades 3rd party libraries used by the toolchain
- upgrades fontbuild code to adjust changes to library APIs
- renames VF font filename extensions to .ttf
- adds better STAT table patch to improve metadata on Windows

misc/fontbuildlib/builder.py

@@ -7,6 +7,7 @@ from fontTools.designspaceLib import DesignSpaceDocument
 from .name import getFamilyName, setFullName
 from .info import updateFontVersion
 from .glyph import findGlyphDirectives, composedGlyphIsTrivial, decomposeGlyphs
+from .stat import rebuildStatTable
 
 log = logging.getLogger(__name__)
 
@@ -81,6 +82,9 @@ class FontBuilder:
     # record is still computed by fonttools, so we override it here.
     setFullName(font, getFamilyName(font))
 
+    # rebuild STAT table to correct VF instance information
+    rebuildStatTable(font, designspace)
+
     log.debug("writing %s", outputFilename)
     font.save(outputFilename)