Update Vignette for R 2.13.0

The Vignette needs to be updated before the release of R 2.13.0 on April 16. Known issues:

2.13.0 requires that Vignettes containing non-ASCII characters load the LaTeX inputenc package and declare their encoding. As I recall, loading inputenc causes fonts to be horribly pixelated when scaled on certain platforms, such as Windows. Wierd bug.

Possible Solutions:
1. Hit comp.text.tex and tex.stackexchange.com and figure out what causes this inputenc bug and how to avoid it.
2. Remove all non-ASCII symbols from the vignette. Currently, these are sets of quotes on lines 465, 472 and 474 that can easily be replaced with `'.
I'm leaning towards option 2 as a quick fix, unless the XeTeX additions currently under review add more UTF8 content to the Vignette.
Updates to the Sweave internals have broken the Mother of All R hacks. Again. Need to make a new driver patch and update patchSweave.R.

Sharpie / RTikZDevice