~jaro/balkon

ref: cf3ec3e35ebdbbe540c0a1490545622157271543 balkon/test/Data/Text/ParagraphLayout/Internal/BiDiLevelsSpec.hs -rw-r--r-- 3.0 KiB
Store default level in BiDiLevels.

This will be required for handling empty text sequences.
Improve BiDi handling of numbers and neutrals.
Add tests for mixed text direction.
Convert legacy span directions into levels.