L2CPBG

Issue:¶

Initial load of large address books (> 1000 contacts) get load more and more slowly as large the addressbook is

Reason:¶

This is mainly founded in a single DB transaction for every single attribute storage

Solution:¶

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.