The inline string struct is actually the same
as the shared strings struct, reuse it.

Note that Go version 1.10 is required.

Fixes #462

* #195: proposed resolution to the issue

* Make GetRows return value avoid empty cell

* Update test file to fix broken testing.

Primary motivation: Avoid statefull tests with not ignorable git file tree changes.
Multiple tests reads and overwrites signle file for won needs.
Multiple tests reads and overwrites file under version control.

Secondary motivation: Minimal tests logic aligment, separate error expectation
and not error expectation tests. Introduce sub-test over test data sets and so far.

This commit is not ideal but necessary (IMHO)

new feature: protect sheet support, relate issue #273

- go test and godoc has been updated

- go test and godoc has been updated

- Fix `checkCellInArea()` index out of range when merged cell ref is single coordinate, relate issue #206;
- go test updated;
- Repository icon for SourceTree has been added

- go test and godoc has been updated

This reverts commit e4611e9e.

- go test and godoc updated

Priority cell style, when the cell and the column at the same time with the style attribute. Relate issue #54 and #56.

- Drawing `nvPicPr` element ID property calculation changed;
- go test updated

- Doc for function `GetRows()` updated, relate issue #43;
- Fix doc typo in `xmlContentTypes.go`;
- Default template updated;
- Readme updated;
- go test updated

- go test updated;
- fix typo and `gofmt -s` formatted

- Update import PKG syntax in struct;
- Update test XLSX file (include table, charts, functions, comments and hyperlink on Sheet1)

- Update test template for this fix

Fix hyperlink missing after save issue and update completion row element logic to enhance compatibility.