bug#39902: 28.0.50; Marking in dired with active region

[Juri Linkov]

>> Thanks for mentioning it.  Now toggling per region is implemented
>> here:
>
> Thanks.
>
> Patch looks reasonable.  I tried it quickly.  It works - but the last
> line covered by the region is never included in toggling, even when it
> is completely inside the region.  I'm using dired-mark-region ->
> inclusive.

Maybe it doesn't work because after Drew asked me to use better names,
I changed the option values from 'exclusive/inclusive' to 'file/line'.
So maybe the patch will work when using dired-mark-region -> line.