### Added
- File logging to `/var/log/ha-backup.log`. Each line has a full date and time,
and the file is appended to on every run.
- New `LOG_FILE` setting in `home_assistant_backup.conf`. Set it to a custom
path, or to `"none"` to disable file logging.
- `ssh`/`scp` error output is also written to the log file.
- Deletions of old local backups are now logged.
### Changed
- All console messages now go through the same logger, so remote cleanup,
notification failures and config validation errors appear in the log too.
- If the log file can't be opened (for example, no write permission to
`/var/log`), a warning is printed and the backup continues without file logging.
- The terminal progress bar stays on the console only and is not written to the log.
phil