add bindings for ess-execute-screen-options

git-svn-id: https://svn.r-project.org/ESS/trunk@5611 0bbaf3bd-34e0-0310-bf65-c717079852d4
correct customization of ess-tracebug-search-path

git-svn-id: https://svn.r-project.org/ESS/trunk@5612 0bbaf3bd-34e0-0310-bf65-c717079852d4