small changes in GAMart and families

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/bayesr@823 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
further dgp's added

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/bayesr@824 edb9625f-4e0d-4859-8d74-9fd3b1da38cb