catch up with R-patched

git-svn-id: https://svn.r-project.org/R/trunk@63269 00db46b3-68df-0310-9c12-caf00c1e9a41
add info on using R for scripting

git-svn-id: https://svn.r-project.org/R/trunk@63270 00db46b3-68df-0310-9c12-caf00c1e9a41