Nested block support to keep data available
It should be possible to reinsert blocks by making a new block denoted by a special meta tag. Older copies would be automatically erased. The previous hash(es) could be in truncated form.
Clients could remember and associate old hashes to new ones, this would preseve file shares or other data.
Blocks should only be nested one level to avoid exponential growth
Deleting a branch is permanent. It CANNOT be undone. Continue?