Emacs doesn't recognize shifted keys in "\C-B" specification

git-svn-id: https://svn.r-project.org/ESS/trunk@5547 0bbaf3bd-34e0-0310-bf65-c717079852d4
correct imenu regexp for methods

git-svn-id: https://svn.r-project.org/ESS/trunk@5548 0bbaf3bd-34e0-0310-bf65-c717079852d4