/File Retrieve glob is case sensitive

[taviso]

A user pointed out over email that the default glob for /File Retrieve is *.wk?, but a user migrating from DOS might reasonably expect their .WK3 files to show up.

Should the default glob include these?

[sjuswede]

That is currently handled by -c lower and -c upper, is it not?

If possible, I would have the default handle both, and the -c options force it to either. That just feels right.