v0.68

• Export with Glyphs build 3135
• Add /Istroke
• Make /acute/grave taller, keep old shorter version in double and case accents
• Make African Eng the default form
• Move alternate /g to CV01 feature
• Improve /t.ss20
• Remove Dutch special glyphs
• Add serifless alternates for /I/J/i/j/l (in character variants 2–4 and stylistic set 3)
• Use correct caron in /Lcaron.ss20