hpa.spatial 0.2.7

• allow map_data_with_correspondence() to take from_geo and to_geo rather
  than only areas and years. (Also requires adding export_fname arg,
  consistent with changes to get_correspondence_tbl().)

• allow get_correspondence_tbl() to take from_geo and to_geo rather than
  only areas and years to get the polygons via get_polygon(). Also allow user
  to specify an export_fname (file name) to save the correspondence table for
  these new tables as they can't be named with make_fname()