Add Google CSE Code and enable a Google custom search

After having gone around on how Atahualpa works and Google CSE works (today),
I have hacked my theme to get a search to work out of the header.
Pretty sure I could add in another theme edit variable (the Google CSE code)
and make it add in the relevant bits. This would be if you had the header search box ON,
then if this yet-to-be-added setting where defined (not blank), it would add in the relevent
bits. This is partly for my own self interest (don't want the next update to blow away
my changes) and partly a contribution so others don't have to do this hack.

I think I can figure this out or would follow the directions on what's kosher
in added such a setting. I can also explain how to make a search results page
work too. See http://snapplus.wisc.edu for what I have going now.

Done things like this before in Moodle and Joomla.
Shoot I'd just edit the Atahualpa source code, if I were made a committer.
Or I could do a diff and send it to whomever.
Just let me know!

--Dirk Herr-Hoyman