Clean up ParagraphConstruction.

Use infix operators for constructing test data.

Implement "plain" interface.

Use Rect in "plain" interface.

Create "plain" interface.

Add module for working with rectangle coordinates.

Add explicit scale to test font.

Clean up and update package description file.

Automatically discover test specs.

Separate tests by module.

Add unit tests for spanToRuns.

Separate modules.

WIP version with WIP interface.