Enabling the option for geometries for ground detectors #91
Description
With the near implementation of a conex-like output, it becomes easier for other experiments to use nuspacesim simulations. This might include ground-based experiments like Auger. Therefore, it would be interesting to allow for the possibility of throwing the events for a ground detector, with the events emerging in the middle of the array. These would require a very simple geometry where all events are thrown isotropically towards a given emerging point, and then they are weighted with the exit probability tables.
