~jaro/balkon

ref: 04fdd17a9811ee19b7ab9537b709171aab2d23a5 balkon/src/Data d---------
Implement absolute line heights with half-leadings.
Calculate "normal" line height and pen position.
Use CSS-compatible line height settings.
Upgrade Fragment to contain pen position.
Use CSS3 terminology for fragments and containing block.
Avoid reimplementing Data.Text.Lazy.fromStrict.
Implement "plain" interface.
Use Rect in "plain" interface.
Create "plain" interface.
Add module for working with rectangle coordinates.
Separate modules.
WIP version with WIP interface.