patch applied (cabal-install): Display the exception for failed downloads

[Duncan Coutts]

Tue Dec 22 05:25:26 PST 2009  Duncan Coutts <duncan at haskell.org>
  * Display the exception for failed downloads
  Not great but better than nothing.

    M ./Distribution/Client/Install.hs -1 +2

View patch online:
http://darcs.haskell.org/cabal-install/_darcs/patches/20091222132526-adfee-b9a457d0a699cceaab256a7de640b37604588551.gz