Add a short example to the messages section again illustrating how
these objects are created, and modify a table float later on to ensure
that all of the many tables in section 4 are placed in section 4
before we start section 5.



git-svn-id: svn://svn.r-forge.r-project.org/svnroot/rprotobuf@861 edb9625f-4e0d-4859-8d74-9fd3b1da38cb