patch applied (cabal-branches/cabal-1.2): Use cpp-options rather than abusing ghc-options

[Duncan Coutts]

Wed Oct 17 09:50:43 PDT 2007  Duncan Coutts <duncan at haskell.org>
  * Use cpp-options rather than abusing ghc-options
  Cabal-1.2 branch version of an equivalent patch in Cabal HEAD

    M ./Cabal.cabal -4 +2