added links to CRAN and the r-forge repository

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/c060@171 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
target="_blank" for the two links

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/c060@172 edb9625f-4e0d-4859-8d74-9fd3b1da38cb