Update to new approaches in testthat and vignettes

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/nlsylinks@109 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Update to new approaches in testthat and vignettes

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/nlsylinks@110 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Update to new approaches in testthat and vignettes

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/nlsylinks@111 edb9625f-4e0d-4859-8d74-9fd3b1da38cb