Support for syncing multiple address books

[kevinkk5]

Please add support for syncing multiple address books instead of chosing between them.
I have one address book for all users on the server and one personal. So chosing between those is not what I would like to do…

So in short: please make it possible to sync address books like the different calendars.

[rfc2822]

Please see the corresponding FAQ entry and follow up in this topic.