Changelog:

• mkfs:
• add option --reflink, when used with --rootdir clone file extents instead of copying (requires source and target image on the same filesystem)
• improved tracking of inodes and subvolumes for option --inode-flags
• fix initializing raid-stripe-tree
• extend what is trimmed/discarded during initialization (temporary chunks, free space)
• check: detect duplicate file names in directory items
• inspect tree-stats: accept string names for option -t
• receive: allow to dump stream from different user
• other:
• updated documentation
• new and updated tests