~jaro/balkon

ref: b27f00d9649dd8faafc91a2333818af233ea0b98 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.