~jaro/balkon

ref: 5b76807e4e2a0b711b110d25719acdd3fea043a4 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.