Move key generate logic from Format to FontData/FillData/...
Can read .xlsx files with font styles now
Can read .xlsx files with fill styles now
Can read .xlsx files with border styles now
Can read .xlsx files with alignment styles now
Fix a silly bug
Add unit test for Worksheet class
Refactor : Worksheet load xml logic
Can read .xlsx files with cols and rows info
Fix friend class statement
Can read .xlsx files with merge cells
Make sure that all examples are console applications
Can read .xlsx files with boolean type cell
Make private class XlsxCellData as public QXlsx::Cell
Improve the QDateTime support
Add new member QXlsx::Document::cellAt()