Fix typo

See merge request !609

These were done with the following commands:

```
cargo set-version -p tor-basic-utils   --bump patch
cargo set-version -p fs-mistrust       --bump minor
cargo set-version -p tor-error         --bump patch
cargo set-version -p tor-config        --bump patch
cargo set-version -p tor-units         --bump patch
cargo set-version -p tor-rtcompat      --bump minor
cargo set-version -p tor-llcrypto      --bump patch
cargo set-version -p tor-bytes         --bump minor
cargo set-version -p tor-socksproto    --bump minor
cargo set-version -p tor-cert          --bump minor
cargo set-version -p tor-cell          --bump minor
cargo set-version -p tor-proto         --bump minor
cargo set-version -p tor-netdoc        --bump patch
cargo set-version -p tor-netdir        --bump minor
cargo set-version -p tor-persist       --bump patch
cargo set-version -p tor-chanmgr       --bump minor
cargo set-version -p tor-guardmgr      --bump minor
cargo set-version -p tor-circmgr       --bump patc...

"Trivial" here includes stuff like cargo reformatting, comment
edits, error message string changes, and clippy warning changes.
Crates that depend on these do not need to increment.

changelog: mention unknown config item messages

See merge request !605

Fix clippy nightly again

See merge request !603

dirmgr: followups to !587, mostly using iterators

Closes #468

See merge request !599

Previously this would eat the first filename!

Found these by disabling the nightly dbg macro special case.  Now, we
have a mechanism for globally adding suppressions to tests, we can use
that instead.

This will allow us to have add_warning manage test lint blocks.

We have to stop printing all the filenames because there are too
many.  Filenames still come out on error of course.

Error refactoring: bytes, cert, proto.

See merge request !604

Some of these were for decoding particular objects (we now say
what kind of objects), and some were unrelated tor_cert errors that
for some reason we had shoved into a tor_bytes::Error.

There is now a separate tor_cert::CertError type, independent from
tor_cert's use of `tor_bytes::Error` for parsing errors.

Failing to encode is fundamentally different from failing to
decode. We now treat those separately, and describe _what_ we failed
to encode or decode.

Replace `base64` crate with `base64ct` crate in `tor-netdoc`

See merge request !600

This avoids adding additional information for now; that will come on
the next commits.

Update all lint blocks

As per the linked discussion.

As per
  #501

We're going to use this to control lints etc.

Since there is currently only one error type that can occur when
encoding, it doesn't make sense to use the full Error type here.

This split will help us downstream, as we no longer need to
categorize tor_bytes::Error as "an error in encoding or decoding".

I considered renaming Error to DecodeError, but that had pretty huge
downstream effects, and didn't seem to be worth it.

Error cleanup, part 1

See merge request !601

These tests are borrowed from other parts of the `tor-netdoc`
crate.

Request for changes: `!600 (comment 2816252)`

As per request, here: `!600 (comment 2816252)`