~jaro/balkon

ref: 3568fab6404744662ff9a2094ebfad8d161fd524 balkon/test/Data/Text 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.