fixed DESCRIPTION files according to CRAN style

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/robast@796 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
a little more details on "contribution" 

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/robast@797 edb9625f-4e0d-4859-8d74-9fd3b1da38cb