Warn users about google

[Mikko V. Viinamäki <Mikko Viinamaki students turkuamk fi>]

Hi!

Looks like the API doc search on http://developer.gnome.org/ is google. There is no indication of that fact before you click. And when you see it, the damage is already done. Some of us want to keep our distance to google, please mark it clearly as google search.

Thanks.

Mikko