~jaro/balkon

ref: a42dd23609b364bf2e4375d8205c1623e4155522 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.