Requires `tcslog` 0.2.
### Changed
- `tcslog-dump --text` now displays payloads as ASCII rather than decoding
them as UTF-8. A printable character prints as itself and everything else
prints as an escape — `\n`, `\r`, `\t`, `\\`, or `\xNN`.
UTF-8 was the wrong thing to ask for of telemetry that is not required to be
text, and `from_utf8_lossy` answered badly in both directions: it replaced
every byte it could not decode with one replacement character, losing which
byte had been there, while passing control bytes straight through to the
terminal — where an escape byte can start a sequence that swallows what
follows and a newline breaks one record across two lines. An escape says
which byte it was and disturbs nothing.
Rendering without the flag is unchanged: each payload byte prints as the
character of that value. The error-recovery suite exercises only that path
and is unaffected.
### Added
- Unit tests for both renderings, covering the ends of the printable range,
the escaped control bytes, bytes above the ASCII range, and a backslash in
the payload — which has to be escaped too, or `\x41` in a payload would read
as the escape for `A`.