A few minor changes from debian packaging fun

[keith-packard]

I'm packaging this for debian and have a few minor changes that I've made:

1. Use QSettings(org, app) instead of QSettings(filename). This lets Qt pick how to store settings, rather than storing them in the same directory as the application binary (which doesn't work on a multi-user system).
2. Use default settings if none were stored. I just used the code in frmsettings.cpp.
3. Allow any filename on the command line. My gcode files have a lot of random extensions.

Thanks for a really useful app; I'm no longer dependent on a Windows VM to drive my laser and router.

[Hostaler]

Hello, I have version 1.2b, I don't know anything about computers, but I've read that you're creating some patches or you already have them created .Will your patches also work for version 1.2b?

[keith-packard]

I don't know; I didn't try applying them to the development version.

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This PR has been automatically marked as stale due to inactivity.

[MarcFontaine]

I'm updating the NixOS package for Candle. Storing the application settings in the usual place is crucial for packaging Candle.

[github-actions[bot]]

This PR has been automatically marked as stale due to inactivity.