~jaro/balkon

ref: 0e108aa71ac0cce0b8d819a0528dba4be37c9bf6 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.