All codes rewritten or adjusted for the change of

All codes rewritten or adjusted for the change of
fontset implementation.  Now fontset is represented by char table.
(Vglobal_fontset_alist, font_idx_temp, my_strcasetbl): Variables
removed.
(my_strcasecmp): Function removed.
(Vfontset_table, next_fontset_id, Vdefault_fontset): New
variables.
(AREF, ASIZE): New macros.
(FONTSET_FROM_ID, FONTSET_ID, FONTSET_NAME, FONTSET_FRAME,
FONTSET_ASCII, FONTSET_BASE, BASE_FONTSET_P, FONTSET_REF,
FONTSET_REF_VIA_BASE, FONTSET_SET): New macros.
(fontset_ref, fontset_ref_via_base, fontset_set, make_fontset,
fontset_id_valid_p, font_family_registry, fontset_name,
fontset_ascii, free_face_fontset, face_suitable_for_char_p,
face_for_char, make_fontset_for_ascii_face, fontset_font_pattern):
New functions.
(fs_load_font): New arg FACE.  Caller changed.
(fs_query_fontset): Argument changed.  Caller changed.
(Fquery_fontset): call fs_query_fontset.
(fs_register_fontset, alloc_fontset_data, free_fontset_data):
Functions removed.
(clear_fontset_elements, check_registry_encoding,
check_fontset_name): New functions.
(syms_of_fontset): Set char-table-extra-slots property of fontset
to 3.  Staticpro and initialize Vfontset_table and
Vdefault_fontset.  Defsubr fontset_font and fontset_list.