Made Summarise generic, adding a method for "glmlist" objects;
Added a coef() method for "glmlist" objects, not yet exported or documented.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/vcdextra@230 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Document coef.glmlist()

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/vcdextra@231 edb9625f-4e0d-4859-8d74-9fd3b1da38cb