Automatically compress the log files

[martinheidegger]

Is your feature request related to a problem? Please describe.

The log files of dat-ssg can become quite big over time. It would be good if it was regularly compressed to make sure that the hard-disk limit isn't exceeded.

Describe the solution you'd like

Once a log file exceeds a size specified in the config (with a preset default), the output/error file gets transformed into a .tar.gz file with the current time/date stamp in the name without interrupting the current process.