MacroFaceIndexing fix

While trying out different permutations of vertex orderings in a macro face, I noticed some kind of anomaly. Andreas dug deeper and managed to find a bug in MacroFaceIndexing.hpp. It seems like the tests had a mistake as well and that is why the bug went unnoticed. We are still unsure why we have never noticed this error in any of our experiments. We can discuss more about this later in our meeting.