patch applied (packages/Cabal): When parsing ghc-pkg output, only look at the first package.conf file for GlobalPackageDB and SpecificPackageDB, and all package.conf files for UserPackageDB.

[Duncan Coutts]

Tue Oct 16 02:52:54 PDT 2007  bjorn at bringert.net
  * When parsing ghc-pkg output, only look at the first package.conf file for GlobalPackageDB and SpecificPackageDB, and all package.conf files for UserPackageDB.
  Before, we would consider user packages when fulfilling dependencies
  for global installs. ghc-pkg will refuse to install packages globally if they
  use user packages. Thus, without this patch, global installs can fail when you have user packages installed.

    M ./Distribution/Simple/GHC.hs -2 +10