add_opt
ret = add_opt(&optlist, optarg, 1);
ret = add_opt(&optlist, optarg, 0);
ret = add_opt(&optlist, optarg, 0);
ret = add_opt(&optlist, optarg, 0);
ret = add_opt(&optlist, optarg, 1);
extern int add_opt(struct options **, char *, int);