Get cfg test cases to 100%
Get cfg test cases to 100%

 * Test cfg.find_config_files() sys.argv usage
 * Test boolean values in cfg config files
 * Finish off incomplete cfg bad value test case
 * Test register_opts() and register_cli_opts()
 * Test the quiet ignoring of option/group re-registration
 * Test cfg print_usage()
 * Test explicit option group titles

Change-Id: Icbe4b7c48d4785551f06873821d1be758adf942c

JioCloud/oslo-incubator,JioCloud/oslo-incubator,JioCloud/oslo-incubator