Generator: text boxes (shape, fill, stroke), inline and display
formulas, comments, bookmarks with cross-references, ruby, rowspan
merges. Display rides a formula owning its line; a stroke width needs
a stroke color; a vertical merge keeps a second column so no row is
all covered cells. Normalize canonicalizes comment ids and dates
(naive local vs UTC are one instant) and trims a formula's latex
(the OMML side keeps the serializer's trailing space on purpose).
Steffen Becker
1c5b6d73d5