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

make the caller of `getRowHeight` function adapt row number change, update comment: use rows number instead of rows index.

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

typo fixed

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

This closes #752, fix incorrectly merged cells on duplicate row, and new formula function: LOWER, PROPER, UPPER

* 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>

Default row height compatibility with Apache OpenOffice and Kingsoft WPS, unit test update and typo fixed