Test paragraphSafeWidth on LTR paragraphs.

Refactor lineNumbers into a common module.

Add centre/right paragraph alignment.

Separate split list functions into a module.

Bump version to 1.2.0.0.

Bump version to 1.1.1.0.

Bump version to 1.1.0.0.

Convert legacy span directions into levels.

Move BiDi Level to separate module.

Add helper function for run-length encoding.

Generalise text from SpanData for other tests.

Prepare for extending ProtoRun.

Bump version to 1.0.0.1.

Consolidate tree types into one.

Handle ancestor boxes in rich layout.

Add ancestor boxes to interface.

Implement finding box edges.

Use ResolvedBox when flattening trees.

Define ResolvedBox.

Separate WithSpan for sharing with other modules.