Reword the beginning of section 4 a bit, and move the
\verb|method(..)| lines into an enumerated list so that we don't
overflow into the margin.



git-svn-id: svn://svn.r-forge.r-project.org/svnroot/rprotobuf@811 edb9625f-4e0d-4859-8d74-9fd3b1da38cb