patch applied (packages/Cabal): Change the checking of new language extensions

[Ian Lynagh]

Sun Dec  7 12:23:15 PST 2008  Duncan Coutts <duncan at haskell.org>
  * Change the checking of new language extensions
  Check for new language extensions added in Cabal-1.2 and also 1.6.
  Simplify the checking of -X ghc flags. Now always suggest using
  the extensions field, as we separately warn about new extenssons.

    M ./Distribution/PackageDescription/Check.hs -25 +54

View patch online:
http://darcs.haskell.org/packages/Cabal/_darcs/patches/20081207202315-adfee-a41be0764fe8ef3f4f7d0e58acb0040dd0733e8b.gz