As outlined in #2199, there may be ways to trigger text layout code
through forward-focus before embedded fonts are registered. To fix this,
this patch replaces the init_code vector, which had the SetFocusItem
code before the font registration, with three explicit vectors for focus
setup code, code from init callbacks, and initial focus, and defines the
order in one central place in the copmiler (iter()).
Fixes#2199