~jaro/balkon

ref: 62b95c9e616030c3a1bdfe158634b2d6ee9fc4a9 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.