Bugfix/copy geogridview
This is the merge request corresponding to issue #52 (closed).
But be warned: I am neither familiar with the gitlab workflow, nor with unit testing in C++, nor with the Dune build system. (To check my extensions of the GoeGrid unit test I built dune modules by myself for the first time. Usually I use a system wide installation of Dune in our work group) Nevertheless, I hope this helps.