~jaro/balkon

ref: 13f4f8e765e5858c8869af76894b52d8a4d5bf6a 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.