Adjust makefile to use a build stamp (untested)
Adjust makefile to use a build stamp (untested)

darcs-hash:20090418113612-adfee-1b04d6bdbae9042c56674073b783e19bbee6d58e.gz

erantapaa/haskell-platform,erantapaa/haskell-platform,erantapaa/haskell-platform,ardumont/haskell-platform,ardumont/haskell-platform,gbaz/haskell-platform,bgamari/haskell-platform,thomie/haskell-platform,gbaz/haskell-platform,bgamari/haskell-platform