quiet
- Don't find "$PATH_PUBKEYS_DIR/" if it doesn't exist
- Retrieve CA comment only inside find, when it's really needed
- Quiet down ssh-keygen in get_ca_sk_comment_from_pk if ca.pub is not
present
- Better explain what it does
- Don't fallback to public key fingerprint in function
- Use "cassh" as the fallback if the comment is empty
- Adjust manpage