adapted for new version of stringr

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/afe@142 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
mail address corrected

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/afe@143 edb9625f-4e0d-4859-8d74-9fd3b1da38cb