patch applied (cabal-install): Add a dependency graph to the InstallPlan

Tue May 6 17:06:26 PDT 2008 Duncan Coutts * Add a dependency graph to the InstallPlan Uses Data.Graph and annoyingly we also need to keep functions around for mapping between Graph.Vertex <-> PackageIdentifier M ./Hackage/InstallPlan.hs -4 +24 View patch online: http://darcs.haskell.org/cabal-install/_darcs/patches/20080507000626-adfee-7...