Hi,

With the following patch one can set the opening via a headline.
Currently, it's pretty conservative and will only set opening if it
isn't set already.  I'm open to discussion on that point.

With this patch, the following example:

--8<---------------cut here---------------start------------->8---
#+TITLE: Test
* my opening
  my letter
--8<---------------cut here---------------end--------------->8---

now exports something like

--8<---------------cut here---------------start------------->8---
[...]
\opening{my opening}
my letter
[...]
--8<---------------cut here---------------end--------------->8---

It applies against master and /not/ Alan's patch from a month ago.

–Rasmus