when creating a manifest from, or validating, a stream like a tar
archive, it requires thinking about some of the functions differently
than walking a directory tree.
This is the beginning of allowing for such features.
Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>
Initially only on linux platform, but could accommodate BSDs as well.
The keyword is rather a prefix of the key. So xattr keyword will have a
prefix of "xattr." followed by a suffix of its namespace and name.
The value stored in the manifest is the SHA1 digest of the extended
attribute's data.
Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>
