Add a RemoveDeadEntries option for knsrc files
If you set RemoveDeadEntries=true, entries whose installed files have all been deleted without going through KNewStuff will be removed from the cache. The removal will happen if, and only if, all listed files were removed, which means that if, for example, an entry was installed from archive, which was decompressed to yield multiple installed files, if even one of those files remains, the entry will remain marked as installed.
This is to help work around people deleting files from underneath KNewStuff, which turns out to happen a lot with e.g. wallpapers and icons.
Only CCBUGing this one, as it is an imcomplete fix for the issue, and requires intervention in the icons.knsrc file for the fix to be applied to the issue mentioned in that bug.