**Dies ist eine alte Version des Dokuments!**

To help to improve our paper, seven people took the time to write a review. For our rebuttal letter, we have worked out and listed all the points of criticism noted from these seven reviews (including the meta-review). Duplications were brought together, but always with a reference to all reviewers who raised this point. This list has been divided into categories for ease of reading, e.g. criticism regarding content, abstract or spelling. In a group conference, each of the points was talked about and it was discussed whether we regard the criticism as unjustified, misunderstood or justified. In the latter case, a solution or implementation of the point of criticism was debated. Finally, we formulated the points of criticism and answers to them for all reviewers in a rebuttal letter. Important for us to underline: we are still open to questions, criticism and discussions (of course especially about the Rebuttal) and would be pleased if we could improve our paper further through a constructive discourse.