Specify use of Pygments

Second argument of ReVIEW::Builder.new() and other Builders is
now a Hash of options for pygments. It defaults to nil which
disables use of Pygments.

* lib/review/review.tex.erb: Move \usepackage{fancyvrb} near the
  other lines needed by Pygments
* test/test_htmlbuilder.rb, test/test_latexbuilder.rb: Add tests
  for pygmentized lists