- Partial logic performance optimization, use pointer reference instead of a pass the variable value;
- Add comments for content types struct definition;
- Update go test `TestSetBorder` section

- Function parameter code is simplified;
- Fix element `Tint` value parsing error in worksheet;
- Update go test

Standard io.Reader and io.Writer capabilities

- Improved performance when reading large files, call Token to read tokens one by one instead Unmarshal. Related issue #20 ;
- Fix go test typo;
- Update README

Add SetRowHeight function

Make functions: `SetCellValue`, `SetCellInt`, `SetCellHyperLink`, `SetCellFormula`, `GetCellValue` and `GetCellFormula` to support the merged cells.

- Character limits for cells added;
- Update go test and fix typo

- Add escape characters of sheet name;
- Update go test and fix typo

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

Setter function to set raw values into a cell

SetCellStr escapes the value in a cell so the excel sheet cannot use the value in formulas.

SetCellDefault accepts a string value and sets it to a cell as a raw value without escaping it

- New functions `GetActiveSheetIndex`, `GetSheetName` and `GetSheetMap` added.

- Update workbook and sheet relationships and self-close tag replacement hack functions

- Compatibility improved: relationship namespace in `workbook.xml` has been changed (`xmlns:mc`, `xmlns:x15` and `mc:Ignorable` added)

- Fix `GetCellValue` causes panic in some particular situation issues;
- Go test updated

- Fix issue XML tag `headerFooter` and `sheetPr` element self-close errors cause file corruption;
- Fix issue `Section` and `Pane` element order make file corruption in some case;
- Change sheet `rId` calculation method in `/xl/workbook.xml`, fix makes file corruption in some case;
- Compatibility improved: add `xlsxTabColor` struct and some XML element for worksheet

- 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.