- go test updated

Signed-off-by: Ri Xu <xuri.me@gmail.com>

- godoc updated

Signed-off-by: Ri Xu <xuri.me@gmail.com>

- API changed, use worksheet name instead of "sheet" + index, related issue #25, #43, #47, #51, #89, #101, #116 and #120.
- go test updated

- Readme and go test updated

- New function `NewStyle()` added and function `SetCellStyle()` has been exported, relate issue #72;
- go test and go doc updated

Function `GetCellValue()` performance improvement by avoid repeating deserialization, relate issue #70.

- Make function `TitleToNumber()` exportable, note that function `ToAlphaString()` return value calculation changes, get more info from go doc. Relate issue #63;
- Readme and go doc updated

- Function `formattedValue()` performance improvement by avoid repeating deserialization, relate issue #64;
- Make function `ToAlphaString()` exportable, relate issue #63

- Handle pre-defined number format set of cell when set cell value with `time.Time` data type, related issue #62;
- go doc updated

- Simplified code

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

- Function `SetCellValue()` support `time.Time` data type parameter, relate issue #49;
- go doc and go test updated

- Optimize deserialization operations;
- README updated, add go version required notice

Performance enhancements, remove redundant XML element checking logic. Relate issue #29. The benchmark report of the current version of this library is shown on the wiki page.

- 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

- 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

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

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

- 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