~jaro/balkon

ref: 4ebfe390a1e8b16f42c6bdb51c135c895a7ce022 balkon/test/Data/Text/ParagraphLayout/Plain d---------
Test ultra narrow Arabic text.
Deprecate the Plain interface.
Add user data to spans.
Qualify Plain interface.
Future-proof records with options.
Qualify Plain ParagraphData.