Update building information about --with-contrib option.
Update building information about --with-contrib option.

darcs-hash:20080624113243-c1071-c77fb3a5a787b47821f2666a3fed2d11128f3fe7.gz

sherwoodwang/wxHaskell,Proclivis/wxHaskell,ekmett/wxHaskell,Proclivis/wxHaskell,thielema/wxhaskell,Proclivis/wxHaskell,sherwoodwang/wxHaskell,ekmett/wxHaskell,sherwoodwang/wxHaskell,sherwoodwang/wxHaskell,thielema/wxhaskell,thielema/wxhaskell,ekmett/wxHaskell,thielema/wxhaskell,Proclivis/wxHaskell