only small touch ups, checked score() function

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/bayesr@803 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
added .Rnw

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/bayesr@804 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
more tests with backfitting

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/bayesr@805 edb9625f-4e0d-4859-8d74-9fd3b1da38cb