patch applied (cabal): Store resolved package description in local build info.

[Ian Lynagh]

Sat Jul 28 15:11:02 PDT 2007  Thomas Schilling <nominolo at gmail.com>
  * Store resolved package description in local build info.  
  
  The clean and sdist commands need to use a flattened representation of
  the original description.  Note the notes for
  flattenPackageDescription for some problems with this approach.

    M ./Distribution/Simple.hs -13 +33
    M ./Distribution/Simple/Configure.hs -20 +3