patch applied (cabal-install): Rewrite getUpgradableDeps so it's simpler and linear time

[Duncan Coutts]

Fri May  9 18:28:16 PDT 2008  Duncan Coutts <duncan at haskell.org>
  * Rewrite getUpgradableDeps so it's simpler and linear time
  Also change so that instead of giving the available package with
  the highest version number (where that is higher than the installed
  package) it gives us a dependency on a version of the package that
  is strictly greater than the one installed. This is more flexible
  since when resolving we do not necessarily have to pick the very
  latest version if that turns out not to be possible.

    M ./Hackage/Dependency.hs -48 +22
    M ./Hackage/Upgrade.hs -10 +3

View patch online:
http://darcs.haskell.org/cabal-install/_darcs/patches/20080510012816-adfee-e683662eaaef4a815e748f3892c90a8d06a8881b.gz