- Move code to include "config.h" into sysdep.h.

- Move code to include "config.h" into sysdep.h.
- Include "cos-i.h".
(concord_close_genre): Move prototype into cos-i.h.
(concord_close_feature): Likewise.
(concord_close_index): Likewise.
(struct CONCORD_Object_Header): Renamed to `COS_Object_Header'; moved
to cos-i.h; add new member `reference_count'.
(CONCORD_OBJECT_TYPE_NULL): Renamed to `COS_Object_Type_NULL'; moved
to cos-i.h; use `enum COS_Object_Type'.
(CONCORD_OBJECT_TYPE_C_STRING): Renamed to `COS_Object_Type_C_String';
moved to cos-i.h; use `enum COS_Object_Type'.
(CONCORD_OBJECT_TYPE_INT): Renamed to `COS_Object_Type_int'; moved to
cos-i.h; use `enum COS_Object_Type'.
(CONCORD_OBJECT_TYPE_DS): Renamed to `COS_Object_Type_DS'; moved to
cos-i.h; use `enum COS_Object_Type'.
(CONCORD_OBJECT_TYPE_GENRE): Renamed to `COS_Object_Type_Genre'; moved
to cos-i.h; use `enum COS_Object_Type'.
(CONCORD_OBJECT_TYPE_FEATURE): Renamed to `COS_Object_Type_Feature';
moved to cos-i.h; use `enum COS_Object_Type'.
(CONCORD_OBJECT_TYPE_INDEX): Renamed to
`COS_Object_Type_Feature_INDEX'; moved to cos-i.h; use `enum
COS_Object_Type'.
(CONCORD_OBJECT_TYPE_OBJECT): Renamed to `COS_Object_Type_DB_Object';
moved to cos-i.h; use `enum COS_Object_Type'.
(struct CONCORD_DS_Table): Renamed to `struct COS_DS_ent'; add new
member `symbol_names'.
(concord_open_ds): Use `COS_ALLOCATE_OBJECT'; initialize
`ds->symbol_names'.
(concord_close_ds): Destroy `ds->symbol_names'.
(struct CONCORD_Genre_Table): Renamed to `struct COS_Genre_ent'.
(concord_ds_open_genre): Use `COS_ALLOCATE_OBJECT'.
(struct CONCORD_Feature_Table): Renamed to `struct COS_Feature_ent'.
(concord_genre_open_feature): Use `COS_ALLOCATE_OBJECT'.
(struct CONCORD_INDEX_Table): Renamed to `struct
COS_Feature_INDEX_ent'.
(concord_genre_open_index): Use `COS_ALLOCATE_OBJECT'.
(concord_index_get_name): New function.
(concord_index_get_genre): New function.