Undo recent changes for restoring it->saved_face_id. Instead,

Undo recent changes for restoring it->saved_face_id. Instead,
set it when it->method is set to next_element_from_display_vector.
(setup_for_ellipsis): Add LEN argument.  Callers changed.
Set it->saved_face_id.
(get_next_display_element): Use loop instead of recursion.
Set it->saved_face_id.  Combine duplicate code for ctr chars.
(next_element_from_display_vector): Do not set it->saved_face_id.
(next_element_from_ellipsis): Use setup_for_ellipsis.