patch applied (cabal-install): Hide any available base and ghc-prim packages from the dep resolver

[Duncan Coutts]

Wed May 21 08:37:00 PDT 2008  Duncan Coutts <duncan at haskell.org>
  * Hide any available base and ghc-prim packages from the dep resolver
  Previously if the base package was available on hackage then the dep
  resolver might try to upgrade it. Unfortunately that's almost
  certainly technically impossible at the moment. So now since the dep
  resolver does not see these available packages it cannot pick them.
  This should fix ticket #174.

    M ./Hackage/Dependency.hs -1 +7

View patch online:
http://darcs.haskell.org/cabal-install/_darcs/patches/20080521153700-adfee-be212625523f47cfa54416ca0f633748af324e7c.gz