Add support for encrypted (and public ed25519 keys) TUF key files.
Add support for ed25519 keys, signatures, and key files in libtuf.py.
Update libtuf.py diagram.
Move canonical encoding operations to the create and verify key functions.
tuf-spec.txt was updated to include the latest metadata changes, such as version numbers, and the "lazy bin walk" scheme was implemented in updater.py.
tuf-spec.txt was updated to include the latest metadata changes, such as version numbers, and the "lazy bin walk" scheme was implemented in updater.py.
Removed checking whether "path_hash_prefix" is consistent with the
delegated paths in the delegator, because now the delegated paths may
list directories instead of simply files.
Removed checking whether "path_hash_prefix" is consistent with the
delegated paths in the delegator, because now the delegated paths may
list directories instead of simply files.