~jaro/balkon

ref: 8ec0fe09ec568b7e5309df9dc37cd3c0f7635283 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.