Found with the showcase documents and by fuzzing the export options through
the round trip and the schemas. ODT: a style's line spacing as a percentage,
section masters laid out from their own zones, variants in schema order, the
watermark on section pages, NCName-encoded style names. DOCX: a section begins
a page, odd/even and w:fmt document-wide, styles with line spacing, shading and
borders, w:numPr and w:pBdr in order. Both importers: the next style, page
setup and text width per section. Editor: chapter counters via counter-set,
a heading in columns stays with its text.