~jaro/balkon

ref: 62b95c9e616030c3a1bdfe158634b2d6ee9fc4a9 balkon/test/Data/Text/ParagraphLayout/Internal/BiDiLevelsSpec.hs -rw-r--r-- 3.0 KiB 
Improve BiDi handling of numbers and neutrals.

Add tests for mixed text direction.

Convert legacy span directions into levels.