~jaro/balkon

ref: 278ffb65d2bef8d684bdd94fd3b1f546efd6a41d balkon/test d---------
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.