patch applied (cabal-install): Fixed error message when some depedencies couldn't be resolved. Before it used show on Dependency, not showDependency.

[bjorn at bringert.net]

Wed Oct 17 12:08:48 PDT 2007  bjorn at bringert.net
  * Fixed error message when some depedencies couldn't be resolved. Before it used show on Dependency, not showDependency.
  Using fail here produces things like:
  cabal: user error (Unresolved dependencies: containers -any, array -any, bytestring >=0.9)
  It would be nice to get rid of the "user error" here. 

    M ./Hackage/Fetch.hs -1 +2
    M ./Hackage/Info.hs -4 +1
    M ./Hackage/Install.hs -2 +3
    M ./Hackage/Utils.hs +6