patch applied (cabal): Make lack of language extensions an error not a warning

Wed Dec 16 12:45:05 PST 2009 Duncan Coutts * Make lack of language extensions an error not a warning Also improve the error message somewhat M ./Distribution/Simple/Configure.hs -3 +5 View patch online: http://darcs.haskell.org/cabal/_darcs/patches/20091216204505-adfee-ce68c746e...