M300433/cdo getopt categories

added categories to cdo_getopt categories can be added with ->set_category("Category") Options that have no category are assigned to the category "Options" Function print_options_help now returns string Function print_options_help now has default parameter category="Options" Added function for category printing handling formatting Streamlined stderr being the taget for cdo_getop Largely removed dependencies on cdo_output by moving almost all printing out of cdo_getopt