fixed bug in gamLine

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/car@374 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
minor change to 'recode' documentation

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/car@375 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
fixed bug in residualPlots(... type='rstudent')

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/car@376 edb9625f-4e0d-4859-8d74-9fd3b1da38cb