update dune.taxon to APG III

git-svn-id: svn+ssh://svn.r-forge.r-project.org/svnroot/vegan/pkg/vegan@2836 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
rda biplot failed with NA scores (like with negative 'scaling' and zero variance species)

git-svn-id: svn+ssh://svn.r-forge.r-project.org/svnroot/vegan/pkg/vegan@2837 edb9625f-4e0d-4859-8d74-9fd3b1da38cb