Regression in keyword passing in XLSXWriter.__init__() causes uncontrolled memory usage

[ShaheedHaque]

The change to XLSXWriter.__init__() in bf0e271:

• causes the intended defaults for constant_memory and default_date_format to be ignored
• makes it impossible to provide overriding values for those defaults

because these two keywords arguments are not passed into the options passed to the underlying xlsxwriter.Workbook(). I think a fix like this is needed:

    def __init__(
        self,
        file_alike_object,
        file_type,
        constant_memory=True,
        default_date_format="dd/mm/yy",
        **keywords
    ):
        if "single_sheet_in_book" in keywords:
            keywords.pop("single_sheet_in_book")
        keywords['constant_memory'] = constant_memory             # <<< new line
        keywords['default_date_format'] = default_date_format     # <<< new line
        self.xlsx_book = xlsxwriter.Workbook(
            file_alike_object, options=keywords
        )