(concord_open_ds): Use <char*> instead of <unsigned char*> for

(concord_open_ds): Use <char*> instead of <unsigned char*> for
location.
(concord_ds_location): Likewise.
(concord_ds_foreach_genre_name): Use <char*> instead of <unsigned
char*> for genre-name.
(concord_ds_get_genre): Likewise.
(concord_genre_get_name): Likewise.
(concord_genre_foreach_feature_name): Likewise.
(concord_genre_get_feature): Use <char*> instead of <unsigned char*>
for feature-name.
(concord_feature_get_name): Likewise.
(concord_obj_put_feature_value_str): Use <char*> instead of <unsigned
char*> for object-id.
(concord_obj_get_feature_value): Likewise.
(concord_obj_get_feature_value_string): Likewise.
(concord_obj_gets_feature_value): Likewise.
(concord_genre_get_index): Use <char*> instead of <unsigned
char*> for index-name.
(concord_index_strid_put_obj): Use <char*> instead of <unsigned
char*> for indexer and object-id.
(concord_index_strid_get_obj_string): Use <char*> instead of <unsigned
char*> for indexer.