moved Rnw files to subdirectory & layout

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/rhrv@150 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
sync

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/rhrv@151 edb9625f-4e0d-4859-8d74-9fd3b1da38cb