patch applied (cabal-install): Add IndexUtils with functions to disambiguate packaage names

[Duncan Coutts]

Fri Jan 18 14:55:45 PST 2008  Duncan Coutts <duncan at haskell.org>
  * Add IndexUtils with functions to disambiguate packaage names
  To allow us to implement case-insensitivity in package names given on the
  command line. We lookup in the package index for packages with the same name
  case-insensitively. If there is no exact match exact case-sensitively and
  there are more than one packages matching case-insensitively then it aborts
  with a message listing the matches. This should not often happen since within
  any single HackageDB server, we can check that packages names are unique
  case-insensitively but it's possible to get ambiguities if cabal-install has
  been configured to use multiple repos.

    A ./Hackage/IndexUtils.hs
    M ./Hackage/RepoIndex.hs +1
    M ./cabal-install.cabal +1