~jaro/balkon

ref: 0e50058d5a6739068d79b08f6fac7fc29aa39f92 balkon/test/Data/Text/ParagraphLayout d---------
Link to Span using a generic wrapper.
Implement absolute line heights with half-leadings.
Use CSS-compatible line height settings.
Fix pretty printing for fragmented spans.
Upgrade Fragment to contain pen position.
Clean up ParagraphConstruction.
Use infix operators for constructing test data.
Implement "plain" interface.
Create "plain" interface.
Add module for working with rectangle coordinates.
Add explicit scale to test font.
Separate tests by module.