- Support for new, OpenType 1.6, mark filtering sets
- When sanitizing, have to do a second round to make sure no toe-stepping
- Implement is_simple()
- Static assert PangoOTGlyph vs hb */
- Face index > 0 and dfont fonts
- HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH vs LookupType::... mess
- Rename LookupFlag::MarkAttachmentType to LookupFlag:IgnoreSpecialMarks
- layout vs font split
- gpi again

In Pango:
- rtla, etc
- cmap14