fixed the IWLS intercept bug

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/bayesr@887 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
still need to look at family argument in bayesr()

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/bayesr@888 edb9625f-4e0d-4859-8d74-9fd3b1da38cb