patch applied (cabal): Add PackageIndex.delete

[Duncan Coutts]

Tue May  6 06:16:03 PDT 2008  Duncan Coutts <duncan at haskell.org>
  * Add PackageIndex.delete
  We occasionally need to remove packages from an index
  eg to restrict the choices of a dependency resolver.

    M ./Distribution/Simple/PackageIndex.hs -1 +14

View patch online:
http://darcs.haskell.org/cabal/_darcs/patches/20080506131603-adfee-ea63571841f7c16a7b4ecf330dcfcaf1f62c9999.gz