Modify Styling options for Excel workbooks. Available parameters can be seen in
excel_output_style() or number_format_style().
set_style_options() sets the styling options for Excel workbooks globally.These
options are used by all tabulation and output functions, which are capable of
exporting styled outputs.
reset_style_options() resets global style options to the default parameters.
get_style_options() prints out the currently set global styling options.
close_file() is a simple, more readable wrapper for setting file parameter to NULL.
set_variable_labels(): Can set variable labels globally so that they don't
have to be provided in every output function separately.
get_variable_labels(): Get the globally stored variable labels.
set_stat_labels(): Can set statistic labels globally so that they don't
have to be provided in every output function separately.
get_stat_labels(): Get the globally stored statistic labels.
reset_qol_options() resets global options to the default parameters.