Replace TrueType-flavored variable font with CFF2-flavored variable font
There's a TrueType-flavored variable font in master, without hinting because ttfautohint does not yet support variable fonts. I'd prefer a CFF2-flavored variable font because I want to make use of CFF2-style hinting. This depends on a few things:
psautohintneeds to grow the capability to hint variable fonts (https://github.com/adobe-type-tools/psautohint/issues/105) or fontTools' varLib needs to support merging individually but compatibly hinted fonts.
- Find out if FreeType, GTK, etc. can actually handle CFF2 variable fonts with hinting correctly.