Update demos for recent changes.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/r2mlwin@291 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Improve consistency in syntax when accessing objects.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/r2mlwin@292 edb9625f-4e0d-4859-8d74-9fd3b1da38cb