[O] Export to Confluence wiki format

[Sébastien Delafond]

Hello,

I've put together a somewhat crude confluence exporter that's based on
the new exporter (as of 7.9.2). For now it's hosted on github[1].

I'm interested in feature requests (as it's only handling basic elements
for now), code style, and pretty much all feedback.

Cheers,

--Seb

[1] https://github.com/sdelafond/org-confluence