~jaro/balkon

ref: cb3f4787147fa665b2f7f8481850751a408fad9d 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.