Added a 'show' method to work more consistently with S4 behavior. Currently duplicates the 'print' method.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/oompa@190 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Added 'show' method wherever there was an S4 'print' method

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/oompa@191 edb9625f-4e0d-4859-8d74-9fd3b1da38cb