on C-c C-t l don't ask for package, when obvious

git-svn-id: https://svn.r-project.org/ESS/trunk@5716 0bbaf3bd-34e0-0310-bf65-c717079852d4
adjust TODO

git-svn-id: https://svn.r-project.org/ESS/trunk@5717 0bbaf3bd-34e0-0310-bf65-c717079852d4