Quicker initial load of large address books > 1000 contacts
Initial load of large address books (> 1000 contacts) get load more and more slowly as large the addressbook is
This is mainly founded in a single DB transaction for every single attribute storage
Bundle all VCF and LCard attribute changes within one large DB transaction.
This should heavily speedup DB storage as well as it make the DB more consistent in that way that we don't have orphaned attribute records in the case of a faulty VCF.