(get_keyelt): Handle an indirect entry with meta char.

(get_keyelt): Handle an indirect entry with meta char.
(describe_vector): Rewrite char-table handling.

(Fmake_keymap): Make a char-table.
(access_keymap, store_in_keymap): Likewise,
(describe_map, Fset_keymap_parent, Faccessible_keymaps): Likewise.
(Fwhere_is_internal, Fcopy_keymap): Handle a char-table.
(copy_keymap_1, accessible_keymaps_char_table): New subroutines.
(where_is_internal_1, where_is_internal_2): New functions.
(syms_of_keymap): Set up Qchar_table_extra_slots prop on Qkeymap.