[racket-dev] Tweaked doc pages

I have the minimal things that I wanted in a working state now:

* Links to the PDF versions next to the version.

* A selection box for different versions of documents.

* A google custom search.

All of this is now visible on newdocs.racket-lang.org, but the older
versions go to the right place on docs.racket-lang.org so you'll get
to the current version of the pages.

Unless there are some objections to all of this, I'll make it go on
docs soon.


About the google search: I'm not too happy about it -- they have
better layouts for the search which I couldn't get to work properly,
but this sucked enough time that I decided to just hack things to some
acceptable state and leave it at that.  If anyone is interested in
improving it, I can tell you how to play with it.  (More higher level
comments in a separate followup that I'll post in a few minutes.)

-- 
          ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
                    http://barzilay.org/                   Maze is Life!