* composite.h (enum composition_method): Delete

* composite.h (enum composition_method): Delete
COMPOSITION_WITH_GLYPH_STRING.
(COMPOSITION_METHOD): Dont' check COMPOSITION_WITH_GLYPH_STRING.
(Vcomposition_function_table): Extern it.
(LGSTRING_XXX, LGLYPH_XXX): Macros moved from font.h.
(composition_gstring_put_cache, composition_gstring_from_id)
(composition_gstring_p, composition_gstring_width)
(composition_compute_stop_pos, composition_reseat_it)
(composition_update_it, composition_adjust_point): Extern them.
(Fcomposition_get_gstring): EXFUN it.