Ingo's patch to make cached imap local subscription work for top-level folders.

"while checking whether GMail can be used as lightweight groupware server. I noticed that local subscription only works for non-top-level folders, i.e. all top-level folders were shown unconditionally and KMail started to sync my kde-commits folder (very bad idea!).

The reason for this problem is that setHonorLocalSubscription( true ) is only called for the ListJobs of subfolders, but not when listing the top-level folders in the namespaces."