* Add funcs to remove sheet from workbook
- RemoveSheet added to remove sheet by index
- RemoveSheetByName added to remove sheet by its name
* Add `CopyRelationship` func to `Relationships`
* Add funcs `CopySheet`, `CopySheetByName`
- `CopySheet` copies sheet at the specified index
- `CopySheetByName` copies sheet with the specified name
* Make `CopyRelationship` return copied rel and bool flag
* Add func `CopyOverride` to `ContentTypes`
* Add test for `CopyRelationship`
* Add tests for sheet removing funcs
* Add test for `CopyOverride`
* Add tests for `CopySheet`, `CopySheetByName`
The go command on Windows doesn't like long path name. To
work around this, this is the first in a series of changes to
shorten the schema disk path structure in a few places.
Fixes#89
This adds support for extracting a cell's formatted value according to
the number format applied to the cell. To do this we need to implement
a parser for Excel style format strings and support formatting numbers
according to that style.
This also enhances the General formatting to be much closer to what
Excel normally does. There are likely still a few corner cases where
Excel and gooxml differ, but hopefully not too many.
This adds comment support for sheets. Excel requires a VML drawing with
the comment box shape for each comment to display the comment.
LibreOffice displays comments fine with or without the shape, and
creates the shape for its own comments. For the sake of compatibility,
we create comment shapes as well.
I know of no other use for the legacy VML support other than comment
boxes...
