[jQuery] ThickBox 3

Cody Lindley updated his ThickBox to version 3 yesterday, but I saw no
announcement :-(
The only thing I didn't see that I was expecting - making the plugin safe
for use with other libraries.
Of course, I'm hoping Jörn will be done with his autocomplete plugin soon
and I can be rid of scriptaculous and not have to work about the
compatibility issue.