~jaro/balkon

ref: 18e994081f0919013b51e3d73cf58022fed3ee6c balkon/test d---------
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.
Automatically discover test specs.
Separate tests by module.
Add unit tests for spanToRuns.
WIP version with WIP interface.