Hello Christoph! Sorry for the late response.

Thanks for the patch, I think it's a good idea to use the standard XDG config/data dirs as you propose. I think I need to refine your patch a bit before I add it though.

I don't like the idea of migrating the config silently behind the user's back. For new users the XDG dir can be used directly, but if the user already has config data in ~/.mhwaveedit, I think the user should be asked whether or not to migrate the data to the XDG dir. Some users maybe only want to test the latest release (or git master) and then go back, they should not have their config zapped. Also, once the data has been migrated the old config should be removed, having config data in two places could create confusion.

Anyway, I will try to get this into the next release.
Thanks again! /Magnus