tweak wording

git-svn-id: https://svn.r-project.org/R/trunk@63238 00db46b3-68df-0310-9c12-caf00c1e9a41
tweak wording

git-svn-id: https://svn.r-project.org/R/trunk@63240 00db46b3-68df-0310-9c12-caf00c1e9a41
Tell emacs to use sh mode
mention differences in gs versions
clarify which part of kmeans


git-svn-id: https://svn.r-project.org/R/trunk@63241 00db46b3-68df-0310-9c12-caf00c1e9a41