Now that we have Config in place, we can enable logging to stream to /var/log/taskotron/taskotron.log. Please adjust the required pieces to log to taskotron.log by default. If the file doesn't exist, emit a warning.

Also, we should provide an option to configure the logging level. I assume this should be available both as a config file option, and as a command line option to runtask. For the command line option, it might be sufficient to add just a simple --debug option (as opposed to --loglevel LEVEL).