* Add craft-sheet: the cell positions, values and tables the spreadsheet formats share
craft-xls carried its own CellRef, Range, Value, CellError, Visibility, sheet-name
quoting, built-in number format table and indexed palette. craft-xlsx and craft-ods
need the same ones, so they move to a crate with no dependencies and craft-xls
re-exports them: an application gets one Value and one CellRef whichever file it read.
Added on the way: A1 parsing (CellRef::parse, Range::parse), Range::count and a1,
CellError::parse and the newer error values SpreadsheetML stores as text,
builtin_format_id for writers.
* Add craft-ods: OpenDocument spreadsheet tables on craft-odf
read() checks the spreadsheet mimetype, refuses an encrypted package, and reads the
tables of content.xml into sheets of cells that keep the file's terms: value type,
the raw value, displayed text, formula text, style name, covered cells, with
repeats expanded and merged ranges. Cell::value() gives the shown value, dates and
durations as serial numbers.
From GridCraft crates/xlsx/src/ods.rs and its tests (7e0d96d7), split from
GridCraft's document model and moved onto craft-odf and craft-xml's pull reader.
Options::only_sheet covers WordCraft's reader of one chosen sheet.
