patch applied (ghc): Better document :stepover and its limitations

[Pepe Iborra]

Wed Aug 22 01:42:54 PDT 2007  Pepe Iborra <mnislaih at gmail.com>
  UNDO: Better document :stepover and its limitations
  
  :stepover only works lexically locally, in the context of the 
  current expression. I have tried to make this point clear
  in the users guide with an example. 
  

    M ./compiler/ghci/InteractiveUI.hs -1 +1
    M ./docs/users_guide/ghci.xml -44 +1