use thing-at-point instead of symbol-at-point

  Fix eldoc bug reported by Sam Steingold.

git-svn-id: https://svn.r-project.org/ESS/trunk@5766 0bbaf3bd-34e0-0310-bf65-c717079852d4
adjust the documentation of ess-inject-source

git-svn-id: https://svn.r-project.org/ESS/trunk@5767 0bbaf3bd-34e0-0310-bf65-c717079852d4
edit newfeat

git-svn-id: https://svn.r-project.org/ESS/trunk@5768 0bbaf3bd-34e0-0310-bf65-c717079852d4
Merge branch 'trunk'