local8Bit encodings scare me, so save the QString in the shared PlaylistItem/CollectionListItem metadata
instead of converting to QByteArray (I don't really think utf-8 would help much since QStrings can buy us
localeAwareCompare as well).

Also use a standard Qt collection for our StringShare instead of a constant sized hash table.  Probably a
better way to do this would be a simple cache that tracks how much each string is put in, not sure how much
that would help though.

svn path=/trunk/KDE/kdemultimedia/juk/; revision=923583