8c9762ee1d
Added whiteout behavior option. ``-o whiteout=always'' is default mode (it is established practice) and ``-o whiteout=whenneeded'' is less disk-space using mode especially for resource restricted environments like embedded environments. (Contributed by Ed Schouten. Thanks) Submitted by: Masanori Ozawa <ozawa@ongs.co.jp> (unionfs developer) Reviewed by: jeff, kensmith Approved by: re (kensmith)