Rename directory named `aux`

[mpilgrem]

It is not possible to git clone this repository on Windows because it has used aux as the name of a directory. AUX is the name of a reserved device in Windows. See: https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file

[sjakobi]

@mpilgrem: We have several symbolic links to the version-compatibility-macros.h file within that aux directory. Will these symbolic links also give trouble on Windows?

[mpilgrem]

@sjakobi, I don't think so. Unless Developer Mode is turned on, a user needs Adminstrator privileges to create symlinks on Windows - however, I think all users can follow (and delete) created symlinks.

The MSYS2 project has some material on symlinks, including a short primer on native Windows symlinks: https://www.msys2.org/docs/symlinks/

[sjakobi]

Thanks for the feedback, @mpilgrem! :) We'll keep the symlinks then, unless anyone reports issues with them.