patch applied (packages/base): Change some imports and derive Show (Either a b)

[Ian Lynagh]

Sun Aug  3 17:41:47 PDT 2008  Ian Lynagh <igloo at earth.li>
  * Change some imports and derive Show (Either a b)
  rather than writing it by hand in GHC.Show

    M ./Data/Either.hs -1 +2
    M ./GHC/Show.lhs -9

View patch online:
http://darcs.haskell.org/packages/base/_darcs/patches/20080804004147-3fd76-d571ba93418f7f386b34755c13943a87dc8ce955.gz