patch applied (cabal-install): Change Dependency module to use the LocalIndex ADT

[Duncan Coutts]

Fri Jan 18 14:07:03 PST 2008  Duncan Coutts <duncan at haskell.org>
  * Change Dependency module to use the LocalIndex ADT
  The whole Dependency module is pure now, no IO since it takes the indexes
  as arguments, rather than the many more args required to do the IO to load
  up the indexes. Much nicer. Also update all callers.

    M ./Hackage/Dependency.hs -70 +46
    M ./Hackage/Fetch.hs -5 +10
    M ./Hackage/Info.hs -1 +6
    M ./Hackage/Install.hs -3 +11
    M ./Hackage/Upgrade.hs -3 +10