Xls Reader Vertical Break and Writer Page Order

[oleibman]

Fix #3305. Xls Reader can set vertical break specifying row 0, causing an exception. It is doubtful that Excel needs a row for a vertical break; code is changed to use row 1 if the input file specifies row 0 (or lower). Code in question has not been exercised in unit test suite. Similarly, code to set horizontal break (which probably does not have a bug) is not exercised in test suite. Finally, page order in Writer incorrectly uses value in opposite way that Reader does. A new sample is added to illustrate that these are all handled correctly; it is easier to verify this by visually comparing the source spreadsheet and the copy made from it. A unit test is also added for the same spreadsheet to formally assert that the 3 properties in question are both read and written correctly.

This is:

- [x] a bugfix
- [ ] a new feature
- [ ] refactoring
- [ ] additional unit tests

Checklist:

• Changes are covered by unit tests
  • Changes are covered by existing unit tests
  • New unit tests have been added
• Code style is respected
• Commit message explains why the change is made (see https://github.com/erlang/otp/wiki/Writing-good-commit-messages)
• CHANGELOG.md contains a short summary of the change
• Documentation is updated as necessary

Why this change is needed?

Provide an explanation of why this change is needed, with links to any Issues (if appropriate).
If this is a bugfix or a new feature, and there are no existing Issues, then please also create an issue that will make it easier to track progress with this PR.

[oleibman]

@MarkBaker Since other comments indicate you are ready for a new release, this probably ought to be part of it (corrects a problem introduced in 1.26 and one that may always have been wrong). I opened it so recently that I just want to make sure you have the opportunity to review before I merge it (or before you do).

[MarkBaker]

@MarkBaker Since other comments indicate you are ready for a new release, this probably ought to be part of it (corrects a problem introduced in 1.26 and one that may always have been wrong). I opened it so recently that I just want to make sure you have the opportunity to review before I merge it (or before you do).

I'd like to get a new release out this weekend if I can, although there's a couple of issues that I'm currently trying to resolve so that they can also be included in that release, Hopefully I'll get them fixed over the weekend.