Significant Update to GenericNetwork functions:
1. get_neighbor_pores and get_neighbor_throats now filter for 'type' again.  This is included in the flatten and stacked returned values.  Documentation is up to date.
2. get_num_neighbors has been added.  This simply returns the number of neighbors, filtered by type.  If ALL pores are sent to this function, it returns an array compatible with pore_properties (i.e. an Np long list).  Docstring may explain more.