[qtcontacts-sqlite] Supply the target aggregate for incidental contact creation

When we create an incidental contact to store data for an existing
contact, the ID of the aggregate for the new contact is already
known.  Supply this information to the save function, so that we do
not need to perform a search for the appropriate aggregate.
Merge pull request #130 from matthewvogt/aggregate-select

[qtcontacts-sqlite] Supply the target aggregate for incidental contact creation