preparing for 2.1 upload.  changed vignette age to remove "sparseMatrix"
removed Rd.sty and Sweave.sty, because R no longer allows it.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/ipmpack@1204 edb9625f-4e0d-4859-8d74-9fd3b1da38cb