Improve existing auto invert feature that uses conic constant to decide to invert wavefront

[gr5]

I have never been super happy about the way DFTF asks if you want to invert the wavefront. Also Yordan asked for the ability to automatically invert related to defocus term as an option instead of the SA term. For spherical mirrors.

I have an idea how to make this easier for users and also add the defocus method.

The popup would give you more options: 4 radio buttons with options to invert manually, invert assuming mirror is partly parabolized, assuming inside focus, or assuming outside focus (4 options). Then it won't ask again until you restart the program or change mirror config settings (if null value changes). Program will have a 5th mode internally which is to ask the user to choose one of 4 options again but if you choose manual it will stop bugging you.

In addition this setting will be visible in the mirror config if you need to change it and it might have the 5th option to "ask me later".

Also save in .OLN files and when loading OLN files if it doesn't match the mirror configuration then either prompt user or (better) just reset things to "ask user" mode again. If config was in "ask user" mode and OLN file has a mode then use the OLN mode for this one igram only.

If I don't get any comments or if only positive comments I'll draw this up visually to make it easier to see, understand, and talk about.