~jaro/balkon

ref: 8b8b095a2d7cc321b520b3d3dc707f3f0501d2e3 balkon/test d---------
Upgrade Fragment to contain pen position.
Clean up ParagraphConstruction.
Use infix operators for constructing test data.
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.