Now we don't have to recreate VaultEditor objects for each file, and so
on. It also paves the way towards specifying separate input and output
files later.
It's unused and unnecessary; VaultLib can decide for itself what cipher
to use when encrypting. There's no need (and no provision) for the user
to override the cipher via options, so there's no need for code to see
if that has been done either.
The --new-vault-password-file option works the same as
--vault-password-file but applies only to rekeying (when
--vault-password-file sets the old password). Also update the manpage
to document these options more fully.
Apart from ansible-vault create, every vault subcommand is happy to deal
with multiple filenames, so we can check that there's at least one, and
make create check separately that there aren't any extra.
