Handle ancestor boxes in rich layout.

Add ancestor boxes to interface.

Add required textDirection to TextOptions.

Deprecate ParagraphConstruction.

Deprecate the Plain interface.

Add public Rich interface.

Add user data to spans.

Add line numbers to laid out fragments.

Qualify Plain interface.

Future-proof records with options.

Bump version to 1.0.0.0.

Mention changed font size in changelog.

Fix compatibility with base < 4.15.

Set release date for v0.3.0.0.

Clarify changelog.

Expose text slicing functions.

Integrate BiDi reordering.

Bump version to 0.3.0.0.

Set release date for v0.2.1.0.

Add paragraph pagination.