[Catalog-sig] New classifiers for Plone

["Martin v. Löwis"]

>       Framework :: Plone :: 3.2
>       Framework :: Plone :: 3.3
>       Framework :: Plone :: 4.0
>       Framework :: Plone :: 4.1
>       Framework :: Plone :: 4.2
>       Framework :: Plone :: 4.3

I have now added these. If you do need the ones with just the major
version, let me know.

Regards,
Martin