(cs_iso8859_1): Deleted.

(cs_iso8859_1): Deleted.
(ft_face_cache): New variable.
(struct ftfont_info): New member fc_charset_idx;
(ftfont_build_basic_charsets): Deleted.
(fc_charset_table): New variable.
(ftfont_pattern_entity): New arg fc_charset_idx.  Store (FILENAME
. FC_CHARSET_IDX) as :font-entity property in the font entity.
Callers changed.
(ftfont_lookup_cache, ftfont_get_charset): New funcitons.
(ftfont_spec_pattern): New argument fc_charset_idx.  Check
registry more rigidly.  Callers changed.
(ftfont_open, ftfont_close, ftfont_has_char): Adjustd for the
change of :font-entity property of the font.