changed link

Hi, on: http://www.haskell.org/bookshelf/ the link for: Online Haskell Course by Ralf Hinze (in German). should be changed from: http://www.informatik.uni-bonn.de/~ralf/teaching/HsKurs_toc.html to: http://www.informatik.uni-bonn.de/~ralf/teaching/Hskurs_toc.html At least my browser seems to be case sensitive. Christian