New exporter: where are the back-end functions called?

[Thorsten Jolitz <tjolitz@googlemail.com>]

Hi Nicolas, Hi List, 

when trying to enhance the HTML back-end of the new exporter with
interactive HTML elements, one possibility (probably the easiest and
best) is to write variants for the export functions for some Org
elements that insert different HTML in the output string (HTML form
fields instead of static HTML).

By far the most interesting Org element for me is the 'headline'
element, that is transcoded by the following function from
'org-e-html.el': 

,--------------------------------------------------------------
| (defun org-e-html-headline (headline contents info)
|   "Transcode an HEADLINE element from Org to HTML.
| CONTENTS holds the contents of the headline.  INFO is a plist
| holding contextual information."
`--------------------------------------------------------------

Now I don't want to mess around in the original exporter code, but
rather would like to rename this function and all the helper functions
it calls with the 'iorg'-prefix and then experiment with changing the
function bodies.

Unfortunately, I cannot figure out where 'org-e-html-headline' is called
in the export process, searching for the function name gave no result. 

Can anybody give me a hint how to find the caller(s) of this function?
Is there Emacs functionality that finds all the callers of a function? I
suspect the call is somewhere concatenated out of different pieces in
the source code, so a simple search won't help probably.

-- 
cheers,
Thorsten