[O] generic page breaks for export?

[Eric Abrahamsen]

It seems like enough of org's export formats have the concept of page
breaks that a generic syntax might be warranted -- I'm finding myself
doing lots of exporting to multiple formats. What do people think of
that? Emacs already has a convention of using ascii 12 as a page
delimiter (though control characters in the buffer look ugly), or we
could introduce something like #+PAGEBREAK, or perhaps both.

If this seems desirable, I'll take a stab at a patch.

Eric