changed identify3d() tto Identify3d(). John

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/car@377 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
improved error checking in recode(). John

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/car@378 edb9625f-4e0d-4859-8d74-9fd3b1da38cb