* Set input encoding in vignette file, not in style file.  Required
  for Sweave to recognize the encoding setting.
* Instead of \usepackage[utf8x]{inputenc}, use
  \usepackage[utf8]{inputenx} and \input{ix-utf8enc.dfu}. The latter
  is the way to go according to vignette("Sweave"). The former command
  would also automatically load the ucs package (see the next point).
* Don't load the ucs package. I don't see a compelling reason why it
  should be loaded. On the other hand, there are claims about
  incompatibilities with other packages. See the following thread:
  https://groups.google.com/forum/#!topic/comp.text.tex/4LC-xODb-LU
* Don't use fancy quotes in the output of the R code in the
  vignette. It seems that these are not present in the default fixed
  width font, resulting in black squares instead of quotes.
* Set the environment variable LANGUAGE to "en" (English) before
  running any R code that produces output. This should override
  automatic translations to languages other than English. In other
  words, the locale used when the vignette is compiled should not
  change the output language anymore.
* Don't use the pdflang option in \hypersetup (PDF
  metadata). Apparently the language is already picked up from the
  language setting of the babel package.


git-svn-id: svn://svn.r-forge.r-project.org/svnroot/dplr@785 edb9625f-4e0d-4859-8d74-9fd3b1da38cb