Each is more correct than every as it is used in this sentence, so
revert back to my previous usage of 'each' here, but keep some of the
other nice improvements that were made to this sentence.



git-svn-id: svn://svn.r-forge.r-project.org/svnroot/rprotobuf@792 edb9625f-4e0d-4859-8d74-9fd3b1da38cb