~jaro/balkon

ref: 13f4f8e765e5858c8869af76894b52d8a4d5bf6a balkon/src/Data/Text/ParagraphLayout/Internal/ProtoLine.hs -rw-r--r-- 3.7 KiB 
Allow explicit control of box collapsing.

Add extensible filter for invisible lines.

Handle ancestor boxes in rich layout.