storing the registry key class name to make PDFXChange-Viewer happy

[Juan Lang]

Hi Patrick,

> There are two different versions of the
> fix. I would prefer the second one because it preserves backwards
> compatibility: In case the key class attribute is set, it is put in
> brackets between the key name and modification time. Otherwise nothing
> changes.

The usual thing is to send your preferred fix to wine-patches and hope
for the best.  See http://wiki.winehq.org/SubmittingPatches for more
details.
--Juan