- Make variable name more semantic
- Reduce cyclomatic complexities for the formula calculate function
- Support specified unzip size limit on open file options, avoid zip bombs vulnerability attack
- Typo fix for documentation and error message

- Rename exported field `File.XLSX` to `File.Pkg`
- Exported error message

This closes #861, support concurrency get cell picture and remove unused internal function `getSheetNameByID`

This closes #652, new SetColWidth API, support set column width in stream writing mode, and export error message

Go 1.15 and later required, #65 fn: IMABS, IMCOS, IMCOSH, IMCOT, IMCSC, IMCSCH, IMEXP, IMLN and IMLOG10

#65 formula function: COMPLEX

typo fixed

lint issue fixed and new formula function: ATAN, AVERAGE, AVERAGEA, CONCAT, CONCATENATE, COUNT, COUNTBLANK, MAX

* use io.Copy from stream temp file to zip Writer

* fix nil

* log

* build

* delete log

* fix compatibility for office

* Update go module
Co-authored-by: Nlijingfeng <lijingfeng@laiye.com>
Co-authored-by: xuri <xuri.me@gmail.com>

* extend cell value load to support custom datetime format

* cleanup incorrect imports

* fix numeric values conversion as done in legacy Excel

* fix tests coverage

* revert temporary package name fix

* remove personal info from test XLSX files

* remove unused dependencies

* update format conversion in parseTime

* new UT to increase code coverage

* Resolve code review issue for PR #703

* Rename broken file name generated by unit test
Co-authored-by: xuri <xuri.me@gmail.com>

* Fixed issue #539 Fixed error opening excel file created in encoding different from UTF-8, added logging of possible errors when decoding XML if the function does not provide exit with an error

* Added test for CharsetReader

* Fixed #discussion_r359397878

Discussion: https://github.com/360EntSecGroup-Skylar/excelize/pull/540#discussion_r359397878

* Fixed go fmt

* go mod tidy and removed unused imports

* The code has been refactored

workBookRelsWriter, drawingRelsWriter into relsWriter;
drawingRelsReader, workbookRelsReader, workSheetRelsReader into relsReader;
addDrawingRelationships, addSheetRelationships into addRels

Fix potential memory leak where zw is not Close() when an error occurs.

add error return value

exported functions:

GetMergeCells
ProtectSheet
UnprotectSheet
UpdateLinkedValue
GetMergeCells
SetSheetVisible

inner functions:

workSheetReader
copySheet

* add new exported function to get Excel file content buffer

* refactor the WriteTo function

- RGBA, HSL color convert has been added;
- go test updated

Extract a WriteTo() method (see io.WriterTo) that exposes the count of bytes
written and rewrite Write() to use it.

- go test and godoc has been updated