patch applied (cabal-branches/cabal-1.2): no longer need to pass --ghc-pkg to haddock

[Ian Lynagh]

Fri Oct 26 00:31:26 PDT 2007  Ross Paterson <ross at soi.city.ac.uk>
  * no longer need to pass --ghc-pkg to haddock
  
  Haddock only runs ghc-pkg if invoked with --use-package, and Cabal no
  longer uses that option, as it now gets the arguments for --read-interface
  from ghc-pkg directly (cf patch "rejig location of package interfaces
  for haddock").

    M ./Distribution/Simple/Haddock.hs -5