(struct CHISE_DS): Change type of location from <char*> to <unsigned

(struct CHISE_DS): Change type of location from <char*> to <unsigned
char*>.
(chise_open_data_source): Change interface.
(chise_ds_close): Renamed from `chise_close_data_source'.
(struct CHISE_Attribute_Table): Add new member `ds'; rename `dbp' to
`db'.
(chise_ds_open_decoding_table): Renamed from
`chise_open_decoding_table' and changed the interface.
(chise_dt_close): Renamed from `chise_close_decoding_table'.
(chise_ds_open_feature_table): Renamed from `chise_open_feature_table'
and changed the interface.
(chise_ft_close): Renamed from `chise_close_feature_table'.
(chise_open_attribute_table): Change interface.