(delacl): Take new parameter to differe between DeleteAll and DeleteDef.
Extend conditional to handle DefaultDef. Change comment accordingly.
(setfacl): Call delacl in DefaultDef case as well.
(usage): Add and describe -k option. Add -k to require options.
(longopts): Add --remove-default option.
(opts): Add -k option.
(main): Handle -k option.