'outline-promotion-headings' is a variable defined in Carsten Dominik's
'outline-magic.el' library (and is thus part of my 'outshine.el' which
merges 'outline-magic').

When I wrote 'navi-mode.el' (see https://github.com/tj64/navi and
http://orgmode.org/worg/org-tutorials/index.html) I tried to make it
dependent mostly on this variable, so I guess I could make navi-mode
work with Org-mode files too (not only with buffers where
outline-minor-mode is acitvated with outshine extensions) if Org-mode
would set this variable: