~jaro/balkon

ref: 13f4f8e765e5858c8869af76894b52d8a4d5bf6a balkon/src/Data/Text/ParagraphLayout/Internal/ParagraphExtents.hs -rw-r--r-- 925 bytes 
Allow paragraphRect without point 0,0.

Parametrise rectangle union bias.

Separate interface-independent constants.