Bug 327315

KAddressbook lists by default all contacts from all resources. Contact items that are in actuality describing the same person but originate from different resources (e.g. from Facebook, Owncloud, local, etc...)  should be consolidated into meta contacts for displaying.

Reproducible: Always

Steps to Reproduce:
1. Add more than one Contacts resource in Akonadi
2. Open KAddressbook
3. Add the same contact to each resource
Actual Results:  
Each contact is listed for each resource separately.

Expected Results:  
Duplicate or Equal contacts should be consolidated into a single meta contact.

Three cases have to be distinguished:

1. The two contact items contain the SAME data, but on different resources (i.e. a local copy + a copy on a cloud instance). In this case only one set of data should be shown.

2. The two contact items each contain only part of the information on the person (i.e. the Facebook account would usually carry different info compared to the cloud contact). In this case both data sets should be displayed.

3. The two contact items have the same name, but describe DIFFERENT people. This means there also has to be a way to avoid grouping on a per-contact basis.