Added max_dist_to_other (default: 1) to ISOVERT_PARAM.
Isovert coord which are further than max_dist_to_other from cube center
are not used to set coordinates in other active cubes.
Added edge_dir to GRID_CUBE. (Not yet used.)
Deprecated options -lindstrom -lindstrom2 -lindstrom_fast -no_lindstrom.
Always compute 3x3 matrix from gradients and apply lindstrom.
(Previously option -lindstrom_fast.)