Deprecate obsolete functions

`hb_ot_tags` replaces `hb_ot_tags_from_script` and
`hb_ot_tag_from_language`.

`hb_ot_layout_table_select_script` replaces
`hb_ot_layout_table_choose_script`.

`hb_ot_layout_script_select_language` replaces
`hb_ot_layout_script_find_language`.
4 files changed