[Bug 49241] (winecfg) Add ability to set windows version to default via command line

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=49241

--- Comment #4 from Austin English  ---
(In reply to Zebediah Figura from comment #3)
> I mean, I'd think the right thing to do is to save and restore version
> around individual verbs, rather than setting it back to the default. Is
> there a reason winetricks doesn't do this?

Yes, I agree. Currently it's not done because it's non-trivial to _get_ the
currently set version, hence, bug 49242 :).

Once that's in place, that's what I'd like to do. Setting the default at that
point would be less important, but still useful.