Make contactsdb use an auto-incrementing index, and start collecting contacts on open window again

For contactsdb we should also use an auto-incrementing index, so that we are not reliant on the email address for adding items to the database. This will help SPAs that are pstn based so that they can show contacts that only have a phone number. Collecting contacts with only a phone number will also work properly.

At some point in some of the refactorings, it appears we stopped collecting contacts when we open the conversation window. We should restore that functionality for now, at least, as this helps in our activities, e.g. dial pad in the pstn spa.