* peertube-import-videos.ts: add --tmpdir <tmpdir> parameter, used to designate working directory for downloading and converting imported videos
* peertube-import-videos.ts: add --first and --last parameters to limit processing of the returned playlist to the first/last N elements
* peertube-import-videos.ts: add --verbose [verbosity] parameter, set this from 0 (only errors are reported) to 4 (for trace debugging), default is 2 (info). When --verbose is used without the optional parameter the logging level is set to 3 (debug). At level 1 (warn) it will only report on successfully uploaded videos (and/or errors), use this when running peertube-import-videos in a cron job to mirror a channel.
* package.json: remove dependency on loglevel
cli.ts: add getLogger(loglevel), to be used in CLI tools, add --verbose to set log level
peertube-import-videos: use getLogger (from cli) instead of loglevel, add error_exit (log error and exit), move --verbose to cli.ts, etc.
* cli.ts: remove superfluous reference to default logging level
* peertube-import-videos: exit_error -> exitError
