patch applied (cabal): Extend and use the OS data type in the package description

[Duncan Coutts]

Mon Mar  3 12:03:38 PST 2008  Duncan Coutts <duncan at haskell.org>
  * Extend and use the OS data type in the package description
  Rather than just using a string. This makes comparing OSs easier since
  we can normalise them once when we parse rather than every time we compare.
  Also makes it easy to discover when a package mentions an unknown OS since
  it's marked as Other "whatever".

    M ./Distribution/PackageDescription.hs -2 +3
    M ./Distribution/PackageDescription/Configuration.hs -16 +11
    M ./Distribution/Simple/Configure.hs -2 +2
    M ./Distribution/System.hs -9 +51

View patch online:

  http://darcs.haskell.org/cabal/_darcs/patches/20080303200338-adfee-ff1eef7267bf9304cd48368dced1a02511695e3d.gz