~jaro/balkon

ref: 8ec0fe09ec568b7e5309df9dc37cd3c0f7635283 balkon/test/Data/Text/ParagraphLayout d---------
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.