[Owncloud] Contacts app in OC 5

[Thomas Tanghus]

Unless there are relevant objections against it, I'm going to merge 
https://github.com/owncloud/core/pull/41 some time Monday.

It might not be the cleanest PR by now, but it was pretty straight forward 3 
weeks ago.

On the plus side it has made me aware of the uphill battle it can be for new 
contributors, so I will remind me to review PRs earlier in the future.

-- 
Med venlig hilsen / Best Regards

Thomas Tanghus